The figure shows three equipotential circles of an isolated point source in vacuum, with the potential zero very far away. (i) The magnitude of the field at A is four times that at B. (ii) The field does no work on a $+1.0\ \mu\text{C}$ charge taken from B to C. (iii) An agent must do $60\ \mu\text{J}$ to take a $+2.0\ \mu\text{C}$ charge slowly from D to A. (iv) The source carries a negative charge. (v) The magnitude of the field at A is $90\ \text{V cm}^{-1}$. How many of the statements above are correct?

Fig. 1: Three concentric circles about a central dot marked source, drawn in a plane, with radii 1.0 cm, 2.0 cm and 3.0 cm marked on a ruler along a horizontal radius. The inner circle is labelled 90 V, the middle circle 45 V and the outer circle 30 V. Five points are marked: A on the 90 V circle, B and C at different places on the 45 V circle, and D on the 30 V circle.