Given the following reasoning and answer, what was the question? It is the duty of waitresses to refill cups. The empty cups are to be refilled by the waitresses at hotels.
 The answer: cup

Show your work and conclude with the exact phrasing "Therefore, the final answer is [answer]." where [answer] is just the final number or expression that solves the problem.
user
The question What do waitresses refill?
Options:
- ball stopped
- coffee shop
- stationery shop
- cup
- restaurant