ANS: A.
B) LHS: (r*s*)*={ε ,r,s,rs....}
RHS:(r+s)*={ε ,r,s,rs,sr...} ,sr can't be generated by LHS...so wrong.
C)(r+s)* - generates all string over {r,s}
(r*+s*) can't generate anything as combination of sr, so wrong.
D) r*s*= {ε ,r,s,rs..} but r*+s* cannot generate rs , so wrong.