still a little confused..

does this do what you want?

=IF(OR(LEN(B2)=0,C2>0),"",IF(AND(VLOOKUP(A2,$A3:$D$99,4,FALSE)=D2,VLOOKUP(A2,A3:$D$99,3,FALSE)>0,B2<MAX(A3:A99)),"Possible",""))