To make an efficient laser while pumping a three-state system, which of the following conditions is necessary? (note: the lowest atomic energy state is referred to as #1, the first excited state [middle energy level] is referred to as #2, and the 2nd excited state [the highest energy state] is referred to as #3)a) The lifetime of the excited energy state at level 2 should be fairly longb) The lifetime of the excited energy state at level 2 should be fairly shortc) The lifetime of the excited energy state at level 2 doesn't matterd) None of the above