You are approaching a drawbridge and have sounded the proper whistle signal requesting it to open. You hear a signal of one prolonged and one short blast from the bridge. Which action should you take?

A
Anchor or use an alternate route because the bridge is out of service for an extended period of time.
B
Approach to a point not closer than 400 yards (360 meters) from the bridge and await further signals.
C
Hold in the channel as the bridge will open within 15 minutes.
D
Approach under full control to pass through the bridge.
E