What does this sign indicate?

A)Exit on a motorway, dual carriageway or road for motor vehicles 300 metres ahead and on the right.Correct
B)Exit 300 metres ahead on the left.
C)Level crossing 300 metres ahead.
The sign indicates on a motorway, dual carriageway or road for motor vehicles that approximately 300 metres ahead there is an exit on the right, since the diagonals ascend from left to right. In addition, the sign will be located on the right-hand side of the road.
If the exit were on the left, the sign we would find would be the following: