The channel under a bridge is marked with lights of the lateral system. The centerline of the channel shall be marked on the bridge by __________.

Correct Answer: Option B — an occulting white light

Per 33 CFR Part 118, bridge navigation lights must clearly mark the channel. The centerline of the navigable channel under a bridge is marked by an occulting white light. This provides a clear visual reference for vessels to maintain a safe course through the center of the span.