The Electric Field Is Zero at Some Point on a Line

The electric field is zero at some point on a line that runs between the centers of two charged spheres.What can one say about this situation?

A) The charges on the two spheres are opposite in sign.
B) The charges on the two spheres have the same sign.
C) The point of interest is equidistant from the two spheres' centers.
D) There is no such point on the line.
E) None are correct.