‘Controlled Airspace’ means all airspace of defined dimensions within which
Why this is the answer
Controlled airspace is airspace of defined dimensions within which an air traffic control service is provided to IFR and, depending on the class, VFR flights (CARs 101.01; TC AIM-RAC). Control zones and SVFR are just features that may exist inside it, not the definition.
Reference
CARs 101.01 – Controlled Airspace TC AIM-RAC – Controlled Airspace
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.