Which of the following term refers to the region of low pressure created when a vibrating object moves backward?

When the vibrating object moves backward, it creates a region of low pressure called rarefaction.

Compression is the area in a longitudinal wave where the particles are close. Rarefaction is the area in a longitudinal wave where the particles are far or apart from each other.

When an object is vibrating, we can hear it because the vibrating object sets the particles to move from their equilibrium position, then the next particle is set to move, and then the next. When the vibrating object pushes the air particles, it creates compression. In contrast, when the vibrating object moves back, it creates a gap, i.e., rarefaction, and with the help of this compression and rarefaction, the longitudinal wave moves.