Concept:In the active region, a transistor is biased so that it can amplify signals.Explanation:For a transistor to operate in the active region, the emitter-base junction must be forward biased and the collector-base junction must be reverse biased.This means one p-n junction is forward biased while the other is reverse biased.Answer:A. one p-n junction is forward biased and the other is reverse biased.