Answer:
3rd image, 2nd image, 1st image, 4th image
Step-by-step explanation:
Not an easy question, tricky one
Electric potential energy is proportional to the magnitude of the charges (the higher the charges, the stronger the Electric potential energy(EPE)) and inversely proportional to the distance between the charges(the longer the distance, the smaller the EPE). U = kQq/r
EPE is positive in this case due to unlike charges.
Between distance and magnitude of the charges, magnitude of charges play a more significant effect than distance (due to Qq , both the magnitude of Q and q affect the EPE)
Hence. zoom in on the magnitude first.
3rd image has the largest + and -, hence greatest magnitude of charges, therefore highest EPE.
Between 1st and 2nd images, charges have the same magnitude, distance now comes to play. Distance between the charges is smaller for image 2 and the charges experience greater EPE. 1st image, the charges are further, hence smaller EPE.
For the fourth image, the magnitude of the charges is the smallest, hence smallest EPE.