Question

trajectory means :
a mental representation of some haunting experience
a progression or course of events, actions, or developments
a superficial aspect as opposed to a things real nature
a group of people having approximately the same age

Explanation:

The word "trajectory" in English commonly refers to a path or course that something follows, which can be related to the progression or course of events, actions, or developments.

Answer:

a progression or course of events, actions, or developments