Explanation
After filing a suspicious activity report (SAR), an investigator should prepare a summary for senior management recommending client off-boarding. This is because client off-boarding is a risk-based decision that requires senior management approval and may involve legal considerations. Informing other local financial institutions about the client, restraining or blocking the client's account(s), or contacting law enforcement directly are not appropriate actions for an investigator to take after filing a SAR, as they may compromise the confidentiality of the SAR, violate privacy laws, or interfere with ongoing investigations.

Explanation
According to the Certified Anti-Money Laundering Specialist (the 6th edition), Section 2.2.5 Suspicious Activity Reporting (SAR) Requirements, a Suspicious Activity Report (SAR) filing is required when a financial institution is aware of, or suspects, a possible violation of law or regulation, or any other suspicious activity related to money laundering, terrorist financing, or other unlawful activity. In this case, Answer A would require a Suspicious Activity Report filing as the deposits are made on a daily basis without providing a legitimate purpose.
According to the Financial Crimes Enforcement Network's (FinCEN) guidance, one example of a suspicious transaction is "frequent deposits of cash or monetary instruments in amounts under $10,000 to the same account, or a pattern of such deposits, unless the financial institution has a reasonable explanation for the pattern." (CAMS Manual, 6th Edition, Page 209)