Over non-populous areas or over open water, a pilot must maintain a minimum distance of ..... feet from any person, vessel, vehicle or structure.
Why this is the answer
Under CAR 602.14(2)(b), away from built-up areas — over non-populous land or open water — an aircraft must stay at least 500 feet from any person, vessel, vehicle or structure.
Reference
CARs 602.14 – Minimum Altitudes and Distances
Question reproduced verbatim from Transport Canada’s PSTAR Study and Reference Guide (TP 11919E). The answer key is Transport Canada’s; the explanation is ours.
A study aid — not a substitute for the official guide, the CARs, or your instructor.