A drawbridge may use visual signals to acknowledge a vessel's request to open the draw. Which signal indicates that the draw will NOT be opened immediately?

Correct Answer: Option D — A fixed red light

Bridge regulations under 33 CFR Part 117 dictate that a fixed red light indicates the draw is not ready for passage and the vessel must wait. This visual signal provides a clear, unambiguous command to the master, preventing premature approach and potential allision with the bridge structure.