Which word refers to the act of chasing or following something?

The term "pursuit" refers specifically to the act of chasing or following something. In a legal and law enforcement context, it often describes the active process of pursuing a suspect to apprehend them or following up on a lead in an investigation. The word conveys a sense of intentionality and focus on the goal of catching or obtaining what one is following, making it well-suited to contexts where chasing or following is involved, such as police work.

In contrast, the other words in the list do not relate to this act of following or chasing. "Quantity" pertains to the measure or amount of something, while "proper" relates to correctness or appropriateness. "Residence" refers to a place where someone lives and does not imply any action of chasing or following. Thus, "pursuit" is the clear choice that captures the idea of actively chasing or following something.