He was angry ___ his brother.

**The reasoning** In English, certain adjectives pair naturally with specific prepositions — we call these **collocations**. When expressing anger directed *at a person*, we use "angry **with**" (or sometimes "angry **at**"). Think of it this way: your anger is *directed toward and interacting with* that person, so "with" creates that connection. Example: "She was angry **with** her friend for being late." This is just how English works — there's no mathematical rule, just patterns you learn through exposure. **Why the wrong options tempt you** - **A) "of"** — You might think of phrases like "afraid of" or "fond of," but "angry of" doesn't exist in standard English. - **C) "to"** — Sounds like you're directing something, but we don't say "angry to" anyone. - **D) "from"** — This suggests distance or origin ("far from," "different from"), not emotional direction. **Quick takeaway** Remember: You get angry **WITH** people, but angry **ABOUT** or **AT** situations — "He was angry with his brother about the mess."