A student walking along a straight hallway records the following consecutive displacements: +4m, +2m, and −9m. The student concludes that their overall displacement is −3m. Which statement best explains the meaning of the negative sign in the result?
a) The student’s overall displacement has a magnitude of 3m; the negative sign is ignored because only distance matters.
b) The negative sign indicates that the student’s average velocity for the trip was −3m/s, meaning the student moved backward the entire time.
c) The student’s final position is 3m on the opposite side of the origin from the positive direction.
d) A negative result means the calculation is wrong; individual displacements must be added using their absolute values.