$\begin {array} {1 1} (a)\;\text{Its emitter junction is in reverse bias and collector junction is in forward bias} \\ (b)\;\text{The transistor must have breakdown region} \\ (c)\;\text{Its emitter junction is in forward bias and collector junction is in reverse bias}\\ (d)\;\text{Its emitter and collector junctions are in forward bias} \end {array}$
