Identifying circuit components from diagrams

Steps:

• Examine choice A for heater and fuse symbols.
• Examine choice B for heater and fuse symbols.
• Examine choice C for heater and fuse symbols.
• Examine choice D for heater and fuse symbols.

Why B is correct:

• Circuit B includes both a resistive heater element and a fuse for overcurrent protection, per standard electrical safety definitions.

Why the others are wrong:

• A lacks a fuse, showing only a heater.
• C has a fuse but no heater, featuring a lamp instead.
• D contains neither, with just a battery and switch.

Not enough information: Choices lack diagrams, making precise identification impossible.

Final answer: B