a 4 microC charge is situated at the origin of an xy coordinate system what is the potential difference between the points x=4m and y = 2m.

Options are
a. -9 x 10^3 V
b. 9 x 10^3 V
c. -36 x 10^3 V
d. 27 x 10^3 V

I ALREADY KNOW THE ANSWER, I NEED THE WORK PLEASE! Answer is B, I know because I guessed. I'm not giving thanks/brainiest if you just say "b"

Thank