You are approaching an open drawbridge and sound the proper signal. You receive no acknowledgment from the bridge. Which action should you take?

Correct Answer: Option D — Approach with caution and proceed through the open draw.

Per 33 CFR 117.15, if a bridge operator fails to acknowledge a signal, the vessel must not assume the bridge is opening. However, if the draw is visibly open, the vessel may proceed with caution. The master remains responsible for ensuring safe passage despite the lack of an audible signal.