whiCh oF thE Following stAtEmEnts BEst DEsCriBEs A lAsEr
A．A DEviCE For stimulAting Atoms AnD molECulEs to Emit light.
B．An Atom in A high-EnErgy stAtE.
C．A tEChniquE For DEstroying Atoms or molECulEs.
D．An instrumEnt For mEAsuring light wAvEs.