When can a service member apply for a leave extension?

A service member can apply for a leave extension at any point before the original leave ends, making it the correct choice. The military recognizes that circumstances can change unexpectedly, leading service members to request additional time off beyond their initially approved leave period. This policy allows for flexibility and considers the various personal situations that may arise.

The option indicating a limitation to just the first three days of leave does not align with military protocol, as it restricts the time frame in which an extension can be requested. Similarly, stating that a request can only be made at the beginning of the leave period does not accommodate changing situations that may occur later during the leave. Lastly, associating the ability to apply for a leave extension solely with outstanding duties implies a condition that is not universally applicable, as any service member can request an extension regardless of their duty status. Thus, the correct answer reflects the most broad and accommodating policy regarding leave extensions.