Refer the image.
kq1q2/r^2 = F
Potential energy = kq1q1/r
The Attempt at a Solution
Obviously since both charges are unequal in magnitude option a is incorrect.
Calculating field at large distance r,
E = kq1/r^2 - kq2/r^2
Also potential energy at q1 is lesser than near q2 for negative charge.
So options c,d are correct. However I don't understand how the angle beta can be calculated from the given information.