A bike rack mounted on your rear bumper partly blocks your licence plate. Does the Act have anything to say about this?

Correct answer: C. Yes — the plate must stay fully visible, and attachments like a bike rack aren't exempt from that duty

Section 13(2) requires every number plate to be kept free from dirt and obstruction and affixed so the entire plate, including the numbers, is plainly visible at all times — specifically naming spare tires, bumper bars, any part of the vehicle, attachments to the vehicle, or the load carried as things that must not obscure it. A bike rack blocking the plate falls squarely within that.

Source: MTO Driver's Handbook: Highway Traffic Act, Part II (Permits) — Section 13(2), number plate to be kept clean and visible