In order to check the performance of a transistor removed from its circuit, what meter or tester should be used?

Correct Answer: Option D — ohmmeter or transistor tester

Transistors are tested by measuring the resistance between their terminals (base-emitter and base-collector) using an ohmmeter. A functional transistor will show specific low-resistance readings in one direction and high-resistance in the other, effectively acting as two back-to-back diodes, or by using a dedicated transistor gain tester.