While loading bulk oil, you notice oil on the water near the barge. Which of the following actions should you carry out FIRST?

Correct Answer: Option A — Stop loading

Immediate cessation of cargo transfer is the primary requirement under 33 CFR 156.120 when a discharge is suspected. Stopping the flow prevents further pollution, allowing the Person-in-Charge to assess the situation, identify the source, and initiate emergency containment procedures before resuming any operations.