Implementing a sound customer due diligence (CDD) program is the most effective way to prevent money laundering through financial institutions, according to experts. CDD is the process of identifying and verifying the identity of customers and assessing their risk profile, source of funds, and expected activity. CDD helps financial institutions to detect and prevent money laundering by enabling them to know their customers, monitor their transactions, and report any suspicious or unusual behavior. CDD is also a key requirement of the international standards and best practices for anti-money laundering and combating the financing of terrorism (AML/CFT), such as the Financial Action Task Force (FATF) Recommendations and the Basel Committee on Banking Supervision (BCBS) Guidelines.
The other options are not as effective as CDD, as they are either too narrow or too broad in scope. Ensuring that transaction monitoring systems can identify terrorist financing is important, but it does not address the broader issue of money laundering, which may involve other types of criminal proceeds or activities.
Collecting information on beneficial owners and foreign customers is a part of CDD, but it is not sufficient by itself, as it does not cover the risk assessment and ongoing monitoring aspects of CDD. Instituting a policy prohibiting the acceptance of funds intended for terrorist financing is a good practice, but it is not a preventive measure, as it relies on the assumption that the funds are already identified as such, which may not be the case.
References:
Customer Due Diligence - FATF-GAFI.ORG
Sound management of risks related to money laundering and financing of terrorism - Bank for International Settlements CAMS Study Guide 6th Edition, page 36-37.

The U.S. Department of the Treasury Office of Foreign Assets Control (OFAC) administers and enforces economic and trade sanctions based on U.S. foreign policy and national security goals. OFAC publishes lists of individuals and entities that are subject to various sanctions programs, such as the Specially Designated Nationals and Blocked Persons List (SDN List), the Sectoral Sanctions Identifications List (SSI List), and the Foreign Sanctions Evaders List (FSE List). These lists are updated frequently and can be accessed through OFAC's website or other sources12.
The Financial Action Task Force (FATF) is an inter-governmental body that sets standards and promotes effective implementation of legal, regulatory and operational measures for combating money laundering, terrorist financing and other related threats to the integrity of the international financial system. FATF publishes lists of jurisdictions that have strategic deficiencies in their anti-money laundering and counter-terrorist financing (AML/CTF) regimes, and calls on its members and other countries to apply enhanced due diligence or counter-measures to protect themselves from the risks emanating from these jurisdictions. These lists are updated periodically and can be accessed through FATF's website or other sources34.
References:
1: CAMS Certification Package - 6th Edition | ACAMS, Chapter 3: Sanctions, p. 63-64 2: U.S. Department of the Treasury Office of Foreign Assets Control, https://home.treasury.gov/policy-issues/financial-sanctions 3:
CAMS Certification Package - 6th Edition | ACAMS, Chapter 4: FATF Recommendations, p. 77-78 4:
Financial Action Task Force, http://www.fatf-gafi.org/countries/#high-risk Reference: https://www.treasury.gov/resource-center/faqs/Sanctions/Pages/faq_lists.aspx#search

The anti-money laundering officer should advise the account-opening officer to verify the identity of all the partners as an initial step. This is because opening a bank account for an offshore company with multiple owners from different jurisdictions poses a high risk of money laundering and terrorist financing. Therefore, the bank should apply enhanced due diligence measures to ensure that the offshore company and its owners are legitimate and not involved in any criminal activities. One of the key measures is to verify the identity of all the partners, not just the one who presents the power of attorney. This will help the bank to establish the beneficial ownership and control structure of the offshore company, as well as to detect any possible fraud, forgery, or coercion in the power of attorney document. The bank should also verify the authenticity and validity of the power of attorney, and the scope and purpose of the authority granted to the partner who requests the account opening.
The other options are less important or irrelevant as initial steps. Verifying the source of the deposit is also a part of the enhanced due diligence process, but it should be done after verifying the identity of the partners and the offshore company. Filing a suspicious transaction report with the appropriate Financial Intelligence Unit or the Egmont Group is a possible action that the bank may take if it detects any indicators of money laundering or terrorist financing in the account opening process, but it is not an initial step. The Egmont Group is an international network of Financial Intelligence Units that facilitates information exchange and cooperation, but it is not a reporting authority.
References:
* ACAMS Study Guide, Chapter 3: Customer Identification and Verification, 1
* ACAMS Study Guide, Chapter 4: Customer Risk Assessment, 2
* ACAMS Study Guide, Chapter 5: Ongoing Monitoring, 3
* Powers of attorney: opening a bank account, 4