The four metals of M, N, X and Y are separately added to hydrochloric acid Reactions only take place in X and Y to produce gas bubbles. When Yis put into the nitrate solution of X, element X is precipitated out. The relative atomic mass of N is greater than that of M. When M is put into the nitrate solution of N, the mass of the solution decreases. The reactivity series for these four metals is A. Y> X > M >N B. Y>X>N>M C. N>M> X>Y D. X >Y > M>Nā