If We have more than one LMD or more than one RMD or more than one Parse Tree, then grammar will be ambiguous:
G1 : for string aa
s->aaB == aa (B->epsilon)
s->AB == aAB (A->aA) == aaAB (A->aA) == aaB (A->epsilon) == aa (B->epsilon)
G2 : for string ab
s->A == ab (A->ab)
s->B == abB (B->abB) == ab (B->epsilon)
Hence G1 and G2 both are ambiguous.
Option C