ATC may authorize a helicopter equipped with a functioning two-way radio to transit a Control Zone under day SVFR where the flight visibility and, when reported, ground visibility are each not less than
Why this is the answer
For day SVFR a helicopter's flight and reported ground visibility need only be at least ½ mile (CAR 602.117(1)(b)(ii)). There is no 500-foot AGL condition attached, so the bare ½-mile option is correct.
Reference
CARs 602.117 – Special VFR Flight TC AIM-RAC – Control Zones, Special VFR Weather Minima
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.