# Assume that an electric field $\bar {E}=30x^2 \hat i$ exists in space. Then the potential difference $V_A - V_O$ , where $V_O$ is the potential at the origin and $V_A$ the potential at $x = 2$ $m$ is :
$\begin{array}{1 1}(A)\;-80\;J \\ (B)\;80\;J\\(C)\;120\;J\\(D)\;-120\;J \end{array}$