The electric field E 1 generated by a, b and Q 1 in Q2 is related to the charge of Q 1, but has nothing to do with the charge of Q2. So, A is wrong and B is right.
According to the formula E=kQr2, c and d know that the size of E 1 is related to the distance between Q2 and Q 1, that is, to their relative positions, so CD is wrong.