A customer is unhappy about a $5,000 loss in a stock that the registered representative...

Step by Step Explanation:

Escalation Requirement: The RR must promptly notify their supervisor or compliance department about the customer’s complaint as required by FINRA rules. Supervisors handle customer complaints according to firm procedures.

Incorrect Options:

B: Reimbursing the customer is not permissible without firm approval and may create compliance issues.

C: Complaints requiring Form U4 updates involve specific allegations such as fraud, not general dissatisfaction.

D: The RR should not contact FINRA directly; the firm will handle communications.