If someone is required to cancel travel plans, which term would be used?

The correct term to use when someone is required to cancel travel plans is "Cancel." This term specifically indicates the action of terminating or voiding an existing travel arrangement. In the context of travel plans, "cancel" clearly communicates that the plans will not proceed as initially scheduled, which is essential for notifying relevant parties and managing other associated logistics.

The use of this term is straightforward and widely understood in both personal and professional travel contexts. It directly conveys the intent and eliminates ambiguity regarding the status of the travel arrangements, making it an essential term in travel management and communication.

In contrast, other options such as "Allotments-Increase," "Change," and "Report" do not accurately capture the action of stopping travel plans. "Allotments-Increase" relates to financial provisions rather than cancellation. "Change" could suggest modifying existing plans rather than voiding them completely. "Report" generally refers to providing information rather than canceling an event or arrangement.