In the question given below, four words are given in

Solution

A-D (luggage ↔ registering): "Luggage" does not fit in the first part of the sentence; "registering a complaint" is the correct phrase. "Luggage" correctly fits in the last part of the sentence. B-C (month ↔ following): "Month up through phone calls" is incorrect; the correct phrase is "following up through phone calls." "For over a month" is the correct usage. Thus, swapping A-D & B-C makes the sentence grammatically and contextually correct. Despite registering ( D ) a complaint at Pune airport and following ( C ) up through phone calls for over a month ( B ), the elderly couple are yet to get their luggage ( A-D (luggage ↔ registering): "Luggage" does not fit in the first part of the sentence; "registering a complaint" is the correct phrase. "Luggage" correctly fits in the last part of the sentence. B-C (month ↔ following): "Month up through phone calls" is incorrect; the correct phrase is "following up through phone calls." "For over a month" is the correct usage. Thus, swapping A-D & B-C makes the sentence grammatically and contextually correct. Despite registering ( D ) a complaint at Pune airport and following ( C ) up through phone calls for over a month ( B ), the elderly couple are yet to get their luggage (A).