The correct option is B 4 N
We know that, the relation between Potential energy (U) and Force (F) is :-
F=−dUdx........(1)
Given, U=−20+(x−2)2
∴dUdx=0+2(x−2)........(2)
Putting (2) in (1),
F=−2(x−2)
at x=0
F=−2(0−2)=4 N
Force on the particle at x=0 is 4 N