Three similar charges +q are placed on 3 corners of an equilateral triangle ABC of side a. How many minimum charges should be placed on a circle of radius a with the center at A so that resultant force on the charge placed at the center is $\frac{q^2}{4\pi {\epsilon }_0{a}^2}$ along x-axis?

• A

  4

• B

  6

• C

  3

• D

  any number