When is it mandatory to operate the speed retarder installed in the vehicle?

1. AWhen driving on a stretch of road before which a sign warning of a skidding hazard is posted.
2. BWhen driving on a stretch of road before which a sign warning of a dangerous descent is posted.
3. CWhen driving on a stretch of road before which a sign warning of a sharp curve is posted.
4. DWhen driving on a stretch of road before which a sign warning of a winding curve is posted.

Pick an answer to test yourself