Complete the sentence: She was annoyed ______ his behavior.

This sentence tests standard English prepositional collocations regarding emotional reactions.

• The preposition at is traditionally used when expressing irritation or annoyance toward an abstract concept, situation, or specific conduct (e.g., "annoyed at his behavior").
• While with is frequently utilized when targeting a person directly (e.g., "annoyed with him"), it is less precise when focusing strictly on the action itself in this context.