Correct Answer - B
(b) Potential energy is only associated with conservative forces.
Force, `F=-((del U)/(del x)hati+(del U)/(del y)hat j+(del U)/(del z)hat k)`
where, F =Conservative force
`((del U)/(del x)hati+(del U)/(dely)hatj+(delU)/(delz)hatk)="Partial derivative of potential energy"`
w.r.t.x,y and respectively.