If the driver is under 21 and holds a provisional license, who in the vehicle must wear seat belts?

This is actually a trick question. The driver and all passengers must wear seat belts, no matter how old the driver is, how much driving experience the driver has, or what type of permit or license the driver holds. [Provisional License for Drivers 16 1/2-20 years old, Grad Program Restrictions, Gradual Rearing of Adult Drivers (GRAD) Program, Types of Driver Licenses and Permits, District of Columbia Driving Manual; and Important Things to Know, District of Columbia Driving Manual]