What does this white marking indicate?

A)The existence of a lane reserved exclusively for buses.
B)It indicates the end of a lane reserved for certain vehicles.
C)It indicates the beginning of a lane reserved for certain vehicles.Correct
The marking in the question indicates the beginning of a reserved lane and marks the start of a lane reserved for certain vehicles. If the inscription BUS also appears inside the lane, it would indicate that it is a lane reserved exclusively for buses.