MATCH THE FOLLOWOIN

In a,c and d : are " pi^ , -pi^ , pk^ " other dipoles or same as the one metiond in the ques.????

I feel , P_o (along x-axis) is the dipole causing Elec. field, and in that field, pi^,-pi^ & pk^ are placed....

lets try assuming this!!!

i think the q says that the angle b/w dipole n e field must be considered frm pi/2 to pi