Passage Summary: An airport can handle 60 landings an hour in good weather but only 30 in bad weather because the runways are too close together. Since airlines schedule flights as if it will always be sunny, bad weather causes major backups.

Reasoning: The physical proximity of runways limits landing capacity during poor visibility, yet airline schedules are built around the higher capacity possible during good weather.

Analysis: This is a Most Strongly Supported question, so we are looking for a logical inference that must follow from these facts. We are told that bad weather reduces capacity by exactly half, from 60 to 30 planes per hour. Since the schedules are based on the 60-plane maximum, any period of bad weather creates a situation where the airport is physically unable to meet the scheduled demand. Look for an answer that connects this specific 50% reduction in capacity to the inevitable accumulation of delays.