Mike Is Walking Down the Street Minding His Own Business

Mike is walking down the street minding his own business when he is stopped by a policeman.Although no crimes have been reported in the area and Mike has done nothing suspicious,the policeman doesn't like the looks of Mike so he conducts a pat down search and finds a tiny bag of marijuana.

A) under these circumstances this is an illegal search under Fourth Amendment protections
B) under these circumstances this is an illegal search under Fifth Amendment protections
C) under these circumstances this is a legal search because illegal drugs were found, justifying the policemen's actions
D) under these circumstances this is a legal search because police are given broad discretion to use their experience to fight crime and obviously the policeman was right in this case