A uniform electric field exists in x -y plane. The potential of points $\;A (2m ,2m) , B (-2m ,2m)\;and\; C(2m ,4m)\;$ are 4V , 16V and 12V respectively . The electric field is

Question

$(a)\;(4 \hat{i}+5 \hat{j})\qquad(b)\;(3 \hat{i}+4 \hat{j})\qquad(c)\;-(3 \hat{i}+4 \hat{j})\qquad(d)\;(4 \hat{i}-5 \hat{j})$