This sign...
A)indicates a mandatory direction on a road with one or more lanes.
B)prohibits changing direction and reversing.
C)allows changing direction but not reversing.Correct
The sign in the question indicates that, on the road extending in the direction of the arrow, vehicles must travel in the direction indicated by it, and that driving in the opposite direction is prohibited. This sign does not prohibit changing direction.
Not to be confused with the mandatory sign "mandatory direction" (round sign), which prohibits changing direction and reversing.