Is it possible for a segment to have more than one bisector? explain your reasoning.

Yes.

A bisector of a line segment is a line which divides the line segment into two equal parts.
A bisector of a line can divide the line in many different ways forming different angles.
A bisector is said to be a perpendicular bisector if the angle at the intersection of the two lines is 90 degrees.
But, there are several other bisectors that are not perpendicular bisectors.

Therefore, it is possible for a segment to have more than one bisector.

The correct answer will be d. -4