In a region of space along the \(x\)-axis, the electric potential as a function of position \(x\) is described by \(V(x) = V_0 \left( \dfrac{x^3}{x_0^3} - \dfrac{3x}{x_0} \right)\), where \(V_0\) and \(x_0\) are positive constants. Which of the following expressions represents the \(x\)-component of the electric field, \(E_x(x)\), as a function of \(x\)?