fill this down in d assuming it stars in row one if not adjust range to suit
=IF(B1="","",SUMPRODUCT(--(B$1:B$1000=B1),--(C1< C$1:C$1000))+1)
since yours starts in a2
=IF(B2="","",SUMPRODUCT(--(B$2:B$1000=B2),--(C2< C$2:C$1000))+1)