Answer:
a. The direction of the electric field is radially inward.
Explanation:
Point charges causes electric field in the radial direction. If the charge is negative, then the electric field is radially inward. If the charge is positive, then E-field is radially outward. In this question, the charge is negative, so it is radially inward.
Since the geometry in the question is not given, I cannot further comment on the problem.