$8$ points$)$: If the electric field is in the positive x direction and has a magnitude given by

E $=$ Cx$2,$ where C is a constant, then the electric potential is given by V $=$

$($a$)3$Cx$3$

$($b$)2$Cx

$($c$)$ Cx$3/3$

$($d$)$Cx$3/3$

$($e$)2$Cx