For transistor action, which of the following statements are correct?

A. Base, Emitter and Collector region have similar size and doping concentrations.
B. The base must be very thin and lightly doped.
C. The emitter junction is forward biased and the collector junction is reverse biased.
D. Both emitter and collector junction all forward biased.

Choose the correct answer from the options given below:

B and C

The correct answer is Option (2) → B and C

(B) for transistor action, the base must be very thin and lightly doped, allowing for effective control of the current between the emitter and collector.

(C) for transistor action, the emitter junction is forward biased, and the collector junction is reverse biased. This allow current to flow from the emitter to the collector through the base.