Except for the purpose of taking off or landing, an aircraft shall not be flown over an aerodrome at a height of less than
Why this is the answer
Per CAR 602.96(4), unless ATC authorizes otherwise, no aircraft may be flown over an aerodrome below 2,000 ft AGL except to take off or land. Lower 'overfly' altitudes are the trap.
Reference
CARs 602.96 – Operations at or in the Vicinity of an Aerodrome, General TC AIM-RAC – Minimum Altitudes – Overflying Aerodromes
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.