A proton is moving in an electric field described by the potential V= x+6. What is the force experienced by the proton?

F = dV/dx

F = q. dv/dx

F = −q. dv/dx

F = −q. dv/dx + qE

A proton is moving in an electric field described by the potential V= x+6. What is the force experienced by the proton F = −q. dv/dx.