How will a molded-case circuit breaker with a thermal trip unit react immediately after it has tripped, as a result of an overloaded motor circuit?

Correct Answer: Option B — The breaker cannot be reset to the ON position until the thermal element cools down.

Thermal trip units rely on bimetallic strips that physically bend when heated by overloads. Per IEEE 45 and 46 CFR Subchapter J, the breaker cannot reset until the bimetallic element cools and returns to its original shape.