Physics, Two charged particles attract each other with a force F. If the charges of both particles are...

Two charged particles attract each other with a force F. If the charges of both particles are doubled, and the distance between them also doubled, then the force of attraction will be
A) F.
B) 2 F.
C) F/2.
D) F/4.
E) none of these

Please, explain in detail

Thank you

the force between two charged particles is

F = k q1 q2/r^2

k is a constant
q1, q2 are the magnitudes of the charges
r is the separation of the charges

if you double each charge, the force increases by a factor of 2 x 2 =4

if you double the distance, the force decreases by a factor of 1/2^2 = 1/4

the combination of these factors is 4 x 1/4 = 1, meaning the force is unchanged, and the correct answer is A

If the charges are doubled, then the force becomes 4F. The distance is doubled, and that divides the force by 4, taking it back to F.

Remember: F=k Qq/r^2