Four charges Q, Q2, Q3 and Q4 of same magnitude are fixed along the x axis at x = -2a, -a, +a and +2a, respectively. A positive charge q is placed on the positive y axis at a distance b>0. Four options of the signs of these charges are given in List I. The direction of the forces on the charge q is given in List II. Match List I with List II and select the correct answer using the code given below the lists. List I List II 6+0, b) Q1, Q2, Q3 Q4 all positive +X Q, Q2 positive; Q3, Q4 negative Q1, Q4 positive; Q2, Q3 negative Q, Q3 positive; Q2, Q4 negative P. Q. R. S. Code: (A) P-3, Q-1, R-4, S-2 (C) P-3, Q-1, R-2, S-4 1. 2. 3. 4. +y -y Q Q (-2a, 0) (-a, 0) (B) P-4, Q-2, R-3, S-1 (D) P-4, Q-2, R-1, S-3 q Q3 (+a, 0) Q4 (+2a, 0)