At what moment did Linda start serving lunch?

The correct answer highlights a specific moment in the sequence of events when Linda was just about to serve lunch. This indicates a sense of immediacy and readiness, suggesting that she was poised to begin the act of serving.

This choice emphasizes anticipation and readiness, reflecting that Linda had completed the necessary preparations, and was literally at the threshold of starting to serve the meal. The clarity in this moment helps understand the nuances of timing in the context of her actions concerning lunch service.

The other choices, while plausible scenarios, do not convey the same level of immediacy as the correct answer. They suggest actions that may precede or coincide with the act of serving but do not specifically capture the "on the point of" serving moment that indicates she was ready to begin. Using this phrasing effectively communicates that she was just about to engage in the act of service itself.