Hold a brief for means to support or defend a person, idea, or cause. The correct answer is this meaning because the expression is used figuratively, not only by its literal words.

Examples:

• The lawyer seemed to hold a brief for the poor villagers.
• In an HSC essay, Hold a brief for can express this meaning: to support or defend a person, idea, or cause.
• When this expression appears in a passage, connect Hold a brief for with the idea of to support or defend a person, idea, or cause.