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.

CFC and HCFC refrigerants are significantly denser than air. When released in confined marine machinery spaces, they accumulate near the deck, displacing oxygen and creating an immediate asphyxiation hazard without necessarily exhibiting warning odors.