Final answer:
A restaurant server is responsible for ensuring drinks have the correct ingredients. Other tasks mentioned are typically not the primary responsibilities of servers but fall to other staff members or are part of general service etiquette.
Step-by-step explanation:
The responsibility of a restaurant server includes making sure drinks have the correct ingredients. Ensuring that the vegetables are properly washed and peeled is typically the task of kitchen staff, while closely monitoring guests' alcohol consumption is a shared responsibility with the bartenders and the management to make sure no laws or regulations are being violated. Observing when guests leave to pick up tips is not a responsibility but part of the servers' work routine, although great service should always take precedence over focusing solely on tips.
In the context of a fast-food restaurant experience, a lunch-hour manager might have responsibilities that include resolving customer complaints and making sure service is fair, fast, and friendly, as illustrated in the given reference story. Actions like implementing efficient solutions to manage customer traffic flow are examples of a manager's task to improve service quality, which could translate to a server's role in the dining context by ensuring efficient and pleasant dining experiences.