All of the three options reflect money laundering risk indicators in relation to a securities account, as they could suggest attempts to conceal the source or destination of illicit funds, or to avoid detection or reporting by authorities. According to the FATF Guidance for a Risk-Based Approach for the Securities Sector1, some of the common indicators of money laundering in securities transactions include:
A high level of activity in securities accounts inconsistent with the customer's profile or investment objectives Frequent or large movements of funds between accounts or institutions, especially involving high-risk jurisdictions or offshore locations Use of debit cards or other payment instruments to access funds from securities accounts Use of complex or unusual transactions or structures without apparent economic or legal purpose References: 1 FATF Guidance for a Risk-Based Approach for the Securities Sector, pages 43-44.

According to the BSA/AML Manual1, one purpose of filing SARs is to identify violations or potential violations of law to the appropriate law enforcement authorities for criminal investigation. Therefore, when an institution receives a document request from law enforcement with regard to an STR that the institution has filed, it should cooperate and provide the documents that were previously collected to support the STR. This will help the law enforcement agency to conduct its investigation and follow up on the suspicious activity reported by the institution. The institution should also maintain the confidentiality of the STR and the document request, and avoid tipping off the customer or any other person involved in the suspicious activity.
References:
BSA/AML Manual1
Answers to Frequently Asked Questions Regarding Suspicious Activity Reporting and Other Anti-Money Laundering Considerations2 Suspicious Transaction Report STR3

The customer's profile and transactions are highly suspicious and indicative of possible money laundering.
The customer's income, source of wealth, and investment plans do not match with the large and frequent transfers from a diamond distributor, which is a high-risk business sector for money laundering. The customer' s transfers to Hong Kong, which is a high-risk jurisdiction for money laundering, also raise red flags. The anti- money laundering specialist should recommend contacting the competent authority and local law enforcement to report the suspicious activity and cooperate with any investigation. This is in accordance with the FATF Recommendation 20, which states that "If a financial institution suspects or has reasonable grounds to suspect that funds are the proceeds of a criminal activity, or are related to terrorist financing, it should be required, by law, to report promptly its suspicions to the financial intelligence unit (FIU)"1. The other options are not appropriate, as they do not address the urgency and severity of the situation.
References: 1: FATF (2012), International Standards on Combating Money Laundering and the Financing of Terrorism & Proliferation, FATF, Paris, France, www.fatf-gafi.org/recommendations.html, p. 19.