Explanation:

- The sentence describes people who are good at noticing and understanding things about social groups.

- "Perceptive" means having the ability to notice and understand things quickly and accurately.

- Option 2: Astute - This word is very similar to "perceptive." It means being clever and having sharp insight, especially in noticing fine distinctions.

- Option 1: Conflicted - This means being confused or having mixed feelings, which doesn't match "perceptive."

- Option 3: Imbecile - This means being very unintelligent, which is the opposite of "perceptive."

- Option 4: Witless - This means lacking intelligence or awareness, again the opposite of "perceptive."

Your Answer: Option 2- Astute