Why can CFC or HCFC refrigerants leaking into a confined space or in limited surroundings cause suffocation?

Correct Answer: Option A — Refrigerants are heavier than air and displace oxygen.

Common CFC and HCFC refrigerants possess vapor densities significantly heavier than air. When leaking into enclosed spaces, they accumulate near the floor and displace breathable oxygen, posing an immediate suffocation hazard.