The correct option is A 7V
As discussed in the videos, this setup, when the current is entering the positive terminal, is called the charging of a battery. Try using Kirchhoff’s loop law as a basic method to solve this. Let’s start from point A and apply Kirchhoff’s law. Now you might ask that this is not even a closed loop, then how can we use loop rule of Kirchhoff’s? Remember loop law is application for any loop, closed or open, but the sum of potential drops will be equal to zero in case of closed loop only.
So let’s give it a try!
VA−5−10×0.2=VB
VA−VB=5+2=7V