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.

Explanation
"'Wash trading' through multiple accounts generates offsetting profits and losses and transfers of positions between accounts that do not appear to be commonly controlled"

Explanation/Reference: https://egmontgroup.org/en/content/membership