Forum:Big burn targetting

alright, if my opponent targets multiple monsters in his graveyard for an effect ie.pot of avarice, Can I activate Big Burn in response? or is it only when the opponent targets a singular monster?

example: Opponent plays Pot of avarice and selects 4 monsters in his graveyard I activate big burn to remove all cards in both of our graveyards, including the ones selected, from play, thus negating pot of avarice's effect and preventing him from drawing