According to Pollution Prevention Regulations (33 CFR), you are required to test cargo discharge piping every __________.

Correct Answer: Option B — 12 months

33 CFR 156.170 mandates that cargo discharge piping systems must be tested annually to ensure integrity. This 12-month inspection cycle is a critical pollution prevention measure, verifying that piping can withstand maximum working pressures and preventing leaks that could lead to unauthorized discharges into the marine environment.