When approaching a level crossing or a movable bridge, when must one exercise extreme caution and reduce speed?

When approaching a level crossing or a movable bridge, when must one exercise extreme caution and reduce speed?
A)Only when they are open.
B)Only when they are closed.
C)Always.Correct
Cases in which speed must be moderated:
- When approaching level crossings, roundabouts and intersections where right of way is not enjoyed, places of reduced visibility or narrowings.