This sign indicates entry is prohibited to...

This sign indicates entry is prohibited to...
A)motor vehicles (automobiles).
B)passenger cars.
C)motor vehicles, except two-wheeled motorcycles without a sidecar.Correct
The sign in the question prohibits entry to motor vehicles, except two-wheeled motorcycles without a sidecar.
The following sign prohibits entry to all motor vehicles including motorcycles.
Do not confuse it with the mandatory sign, which requires automobiles, except motorcycles without a sidecar.