[单选题]
A simple junction transistor consistsr6, w lojtrhukp-w d32ys5 0+hnw0 5eq of three semicondu.q 5vko6tw3s r)yi aac;y9l7u ctor sections consisting ocl. atw3;uayky)r sqi75v9 o6 f
A. pnp semiconductors.
B. npn semiconductors.
C. either pnp or npn semiconductors.
D. none of the given answers
