A4 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 ! answer is b, i know because i guessed. i'm not giving /brainiest if you just say "b"