The correct answer is **may** (Option 3). **Comprehensive Derivation:** The correct answer is - "may" Explanation & Key Takeaways: • From the given options, the most appropriate answer is "may". • May is used to denote possibility of an event about to happen. • Eg. It may rain tonight. • Given sentence shows the possibility of arrival of Peter. • Let us see the meanings of the given options - • Shall - to denote command, promise, threat, determination, complusion, and advice. • Eg. You shall leave the room at once. • Could - to denote past capability, ability, power. • Eg. I could eat 10 chapatis when I was young. • Will - in context of future tense for similar case as for shall. • Eg. I will punish you. • Thus, Option 3 is correct answer. **Option Elimination:** • **Option 1 (shall)**: Incorrect distractor. • **Option 2 (could)**: Incorrect distractor. • **Option 3 (may)**: Correct Answer; accurate according to canonical reference. • **Option 4 (will)**: 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: may corresponds to Option (3).