It could be REM for two reasons - the other bands are both Australian, REM are American, and the other two have both lst their original singers - drinking in the case of AC/DC's Bon Scott, and suicide for INX's Michael Hutchence.
Or it could be INXS, as AC/DC and REM are properly used abbreviations for Alternating Current/Direct Current and Rapid Eye Movement, whilst INXS is just made up and not in general use.
If you want to be really clever, you could say that, while AC/DC and INXS are famous for losing their singers, REM are famous for losing their religion!