Physics help ~~ MCQ~~?

Two charges of equal magnitude Q are held a distance d apart. Consider only points on the line passing through both charges.

Part A
If the two charges have the same sign, find the location of all points (if there are any) at which the
potential (relative to infinity) is zero.

A) Midway between charges
B) At the points, where the charges are
C) There are no such points

Part B
If the two charges have the same sign, find the location of all points (if there are any) at which the electric field is zero.

A) Midway between charges
B) At the points, where the charges are
C) There are no such points

Part C
If the two charges have opposite signs, find the location of all points (if there are any) at which the potential (relative to infinity) is zero.

A) Midway between charges
B) At the points, where the charges are
C) There are no such points

Part D
If the two charges have opposite signs, find the location of all points (if there are any) at which the electric field is zero.

A) Midway between charges
B) At the points, where the charges are
C) There are no such points