Next question, question says the electric dipole, when plays in a uniform electric field will have minimum potential energy, if the positive direction of the dipole moment makes the follow angle with E, our option is pi pi by 2, 0 or 3 pi by 2, very easy question, again if it definitions will be, so this is the thing that you should know that this is your electric field, and if you have kept the dipole here, this is the diameter, then this is your dipole, this is your angle theta, so here when we write the potential energy, u, delta u, we write it minus pi cos theta, and if your dipole is kept on this, then in its case theta will be zero degree, so implies your delta u is minus pi, so based on this we can say that minimum potential energy will be added when your angle is zero degree, and hence option number c, zero would be the right answer.