When reversing to park...

A)you must activate the hazard warning lights.
B)the maneuver may not last more than 15 seconds.
C)it is not permitted to travel more than 15 meters or encroach on a road junction.Correct
As a general rule, reversing is prohibited, except in the following cases on an exceptional basis and always covering the minimum necessary distance:

1. As a complementary maneuver for stopping, parking, or joining traffic. In this case, the reversing distance may not exceed 15 meters or encroach on a road junction.
2. When it is not possible to move forward or change direction or sense of travel. In this case there is no limit on the reversing distance, and it may even encroach on a road junction if necessary.

Reversing is prohibited on dual carriageways and motorways.