You need to twist right around in your seat to see properly while reversing, and your seatbelt is stopping you. May you unbuckle?

Correct answer: D. Yes — the belt may come off while reversing, but must go back on before you move forward

Yes. This is one of the few places the Handbook explicitly relaxes the seatbelt rule: "You don't have to wear a seatbelt while backing up. If you need to remove your seatbelt to turn your body to see properly when reversing, do so. But don't forget to buckle up again before moving forward." The law behind it is HTA s.106(6)(a), which exempts from the seatbelt requirement a person "who is driving a motor vehicle in reverse." Seeing where you are going matters more here than restraint does, because reversing happens at walking pace and the thing you are most likely to hit is a person you never saw. The Handbook wants you turned sideways and looking over the shoulder on the side you are moving toward — mirrors and cameras supplement that, they do not replace it. The trap in this rule is the last clause: the belt has to be back on before you move forward again.

Source: MTO Driver's Handbook: Changing directions — Backing up, seatbelt while reversing