When there is a deviation from a VFR flight plan, ATC shall be notified of such deviation
Why this is the answer
Per CAR 602.76 (Changes in a Flight Plan), a pilot must notify ATC of any deviation from a VFR flight plan (route, duration, or destination) as soon as practicable — not on a fixed timetable. Prompt notice keeps the flight-following and SAR picture accurate.
Reference
CARs 602.76 – Changes in a Flight Plan TC AIM-RAC – Changes to the Information in a Flight Plan or Flight Itinerary
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.