There is a uniform electrostatic field in a region. The potential at various points on a small sphere centred at P in the region is found to vary between 589.0 V and 589.8 V. What is the potential at a point on the sphere whose radius vector makes an angle of 60∘ with the direction of the field?
a. 589.5 V
b. 589.2 V
c. 589.4 V
d. 589.6 V