Electric Field and Potential : the Potential as a Function

Electric field and potential : The potential as a function of position x is shown in the graph in the figure. Which statement about the electric field is true?

A) The electric field is zero at x = 0, its magnitude is at a maximum at x = 5 cm, and the field is directed to the right there.
B) The electric field is zero at x = 5 cm, its magnitude is at a maximum at x = 0, and the field is directed to the right there.
C) The electric field is zero at x = 0, its magnitude is at a maximum at x = 15 cm, and the field is directed to the left there.
D) The electric field is zero at x = 10 cm, its magnitude is at a maximum at x = 5 cm, and the field is directed to the left there.