A point of departure means a starting point for discussion, study, or change. The correct answer is this meaning because the expression is used figuratively, not only by its literal words.

Examples:

• The poem became a point of departure for the class discussion.
• In an HSC essay, A point of departure can express this meaning: a starting point for discussion, study, or change.
• When this expression appears in a passage, connect A point of departure with the idea of a starting point for discussion, study, or change.