(a) Electrons crossover from emitter to collector

(b) Holes move from base to collector

(c) Electrons move from emitter to base

(d) Electrons from emitter move out of base without going to the collector

Answer:

The correct options are

(a) Electrons crossover from emitter to collector

(c) Electrons move from emitter to base

Explanation:

Forward bias from emitter to collector repels electrons; 5% of electrons combine with holes in the base, while the rest are repelled. The reverse bias of the collector-base junction attracts 95% of the emitter’s electrons.
As a result, electrons travel from emitter to collector via the base, proving (a) and (c)