Which feature of a flexible premium annuity provides the owner with increased control over payments?

The feature that provides the owner with increased control over payments in a flexible premium annuity is the ability to make additional payments. This feature allows the annuity owner to contribute varying amounts of money over time rather than being limited to a fixed premium schedule. This flexibility enables the owner to increase their investments based on their changing financial circumstances or goals, such as making larger contributions during better financial periods or smaller ones during leaner times.

In contrast, fixed payments only restrict the owner to a predetermined payment amount, thereby limiting their control. The length of the payment period does not directly influence the owner's ability to adjust contributions, and the type of death benefits available pertains more to the inheritance aspect of the annuity rather than the payment control features.