设A ,B ,C 均为n 阶可逆矩阵,则下列等式成立的是（ ）．
A.(A + B)^2 = A^2 + 2AB + B^2 B.(A + B)B = BA+B^2
C.(2ABC)^−1 = 2C ^−1B^ −1A^−1 D.(2ABC)′ = 2C′B′A′