Final answer:
The airplane would have to fly 200 km east to arrive back at City A.
Step-by-step explanation:
An airplane flies 200 km due west from City A to City B. The correct answer is A) 200 km east.
The airplane flies due west from City A to City B, so to return to City A, it needs to fly in the opposite direction, which is due east.
Therefore, the airplane would have to fly 200 km east to arrive back at City A.