The correct option is D Positive, negative or zero
Displacement is the shortest possible distance. And It can be negative, positive or even zero
Displacement is negative when- Suppose, a person starts from a given point X and move 50 m straight forward and then turns back and moves 60 m straight. Clearly, he / she has moved an extra 10 m. And it will be termed as negative displacement because of the opposite direction.
Displacement is positive when a person moves from point X to pint Y. He/She has covered certain distance and it can be termed as my positive displacement.
Displacement is zero when a person moves from point X to point Y and then back to point X. This will create 0 displacement as the starting and ending points are same (For example: (One round of a circular track).