Which of the following could increase the workload of a crew?

In a crew environment, workload can refer to the amount of tasks or responsibilities that crew members must manage during a flight. Each of the factors listed contributes to increasing this workload.

Flight delays can complicate the operational schedule for crews, causing additional tasks such as dealing with passenger concerns, coordinating with ground staff, and managing time-sensitive duties.

Extended flying hours require crew members to stay alert and focused for longer periods, which can increase fatigue and the need for additional breaks, thus adding to their responsibilities.

An increased number of passengers leads to more interactions and potentially more complex logistical considerations, such as boarding, in-flight service, safety briefings, and responding to passenger needs.

When all these factors occur simultaneously, they significantly compound the workload of the crew, making the cumulative impact even more substantial. This makes "all of the above" the most comprehensive answer, as each individual factor can increase workload independently, and together, their effects are amplified.