Final answer:
The plastic insulation on live/hot wires is designed to prevent both shock hazards by insulating against electric currents and thermal hazards by slowing down thermal transfer that could lead to fires.
Step-by-step explanation:
The insulation on live/hot wires serves as a protective barrier to prevent electrical current from coming into contact with people or objects that may conduct electricity, which could lead to an electric shock hazard. Additionally, insulation slows down the thermal transfer, protecting against thermal hazards that can arise from overheating wires, potentially preventing situations such as fires within the walls of a house due to excessive electrical heating. Therefore, the correct answer is c) Prevents both shock and thermal hazards.