According to the ACAMS study guide, one of the best practices for dealing with law enforcement inquiries is to verify the identity and authority of the law enforcement officer before providing any information (p. 224).
This is to ensure that the inquiry is legitimate and not a phishing attempt or a breach of confidentiality. The compliance officer should also document the inquiry and the information provided, and consult with legal counsel if necessary. The other options are not appropriate, as they may either violate the law, compromise the investigation, or create unnecessary work.
ACAMS. (2020). Study Guide for the Certification Examination for Anti-Money Laundering Specialists (6th ed.). Miami, FL: ACAMS.
What Is An AML Officer1

Financial Intelligence Units (FIUs) are the primary channels for sharing financial intelligence both within countries and across borders. FIUs cooperate with each other and other relevant law enforcement, regulatory, or intelligence agencies in the fight against money laundering, terrorism financing, and other financial crimes.

Layering is the second stage of the money laundering process, in which the launderer moves the funds around to create distance and confusion between the source and the destination of the illicit proceeds. Layering often involves multiple transactions, such as wire transfers, shell companies, trusts, and offshore accounts, that make it difficult to trace the origin and ownership of the funds. Layering is intended to disguise the audit trail and provide anonymity for the launderer12.
Placement is the first stage of the money laundering process, in which the launderer introduces the illicit proceeds into the financial system, often by breaking them into smaller amounts or using cash-intensive businesses12.
Structuring is a technique used in the placement stage, in which the launderer deposits or withdraws cash in amounts below the reporting threshold to avoid detection or suspicion12.
Integration is the third and final stage of the money laundering process, in which the launderer reintroduces the funds into the legitimate economy, often by purchasing assets, investing in businesses, or mixing them with legal income12.
1: ACAMS (2020), Study Guide for the Certification Examination, 6th Edition, ACAMS, Miami, FL, USA, www.acams.org/en/cams-certification-package-6th-edition, pp. 12-14. 2: ACAMS (2020), CAMS Examination Preparation Video, 6th Edition, ACAMS, Miami, FL, USA, www.acams.org/en/cams- certification-package-6th-edition, Module 1.

B: An internal auditor with the requisite knowledge and expertise of AML: An internal auditor with sufficient knowledge and expertise in AML regulations and compliance requirements can perform the AML audit.
D: Qualified bank staff if not involved in the AML function being tested: Qualified bank staff who are not involved in the AML function being audited can perform the AML audit.

Financial Intelligence Units (FIUs) are national agencies that collect, analyze, and disseminate information on suspicious or unusual financial activity, such as money laundering and terrorist financing, to relevant authorities. One of their main functions is to disseminate the results of their analysis to law enforcement agencies in a timely manner, so that they can initiate investigations or prosecutions. This is also one of the standards set by the Financial Action Task Force (FATF), the global body that sets the anti-money laundering and counter-terrorist financing (AML/CFT) policies and recommendations. The other options are not the primary responsibilities of FIUs, although they may perform them as part of their mandate or in cooperation with other agencies.
What are Financial Intelligence Units (FIUs)? | Dow Jones
Financial Intelligence Units: An Overview - IMF
Financial Intelligence Units - Egmont Group
FATF Recommendation 29 - Financial Intelligence Units (page 17)
Reference: https://knowledgehub.transparency.org/assets/uploads/helpdesk/Financial-Intelligence- Units_Design-Mandate-Powers_2019_PR.pdf