A regulatory "No Standing" sign is posted with arrows showing the zone it covers. What does "no standing" mean, as distinct from "no parking"?

Correct answer: D. You may only make a brief stop to receive or discharge passengers, not to load or unload goods, which a no-parking zone still permits

The Highway Traffic Act defines "standing," when prohibited, as halting a vehicle except while actually receiving or discharging passengers — narrower than "park"/"parking," which the Act allows to include a brief halt for loading or unloading merchandise as well as passengers. A no-standing zone permits the passenger stop but not a goods stop.

Source: MTO Driver's Handbook: Highway Traffic Act, s. 1 — definitions of "standing" and "park"/"parking" when prohibited