The correct answer is **-cal** (Option 2). **Comprehensive Derivation:** The correct answer is - "cal" Explanation & Key Takeaways: • From the given options, the most appropriate answer is "cal". • Option 3 and 4 makes the word meaningless so they are incorrect. • Option 1 makes the reciprocity means the practice of exchanging things with others for mutual benefit that is not appropriate here. • Reciprocal means involving two or more people or groups who agree to help each other or to behave in the same way towards one another • Eg. This reciprocal silence is probably significant. • In this way, Reciprocal is appropriate with the context of the sentence. • Thus, Option 2 is correct answer. **Option Elimination:** • **Option 1 (-city)**: Incorrect distractor. • **Option 2 (-cal)**: Correct Answer; accurate according to canonical reference. • **Option 3 (-ment)**: Incorrect distractor. • **Option 4 (-en)**: Incorrect distractor. **Exam Trap:** Be careful of misleading distractors and subtle terminology differences. Verify core properties before selecting your answer. **Memory Booster:** Core mnemonic rule: -cal corresponds to Option (2).