Which type of annuity involves a lump sum or payments available at maturity?

The correct answer involves understanding the characteristics of the various types of annuities, particularly those that relate to disbursement at maturity. A two-tiered annuity is designed to allow for both a lump sum payment or periodic payments distributed based on the performance of underlying investments at maturity or another specified time.

In contrast, a single premium annuity is funded by a one-time payment but does not specifically denote a lump sum at maturity. A deferred annuity, while it does allow payments to be made at a later date, typically accumulates funds over time and disburses them later, which may not be strictly defined as available "at maturity." A variable annuity provides payments that fluctuate based on the performance of investment options chosen by the annuitant; while it could involve lump-sum payments, the nature of the payments can vary significantly.

Therefore, the defining trait of the two-tiered annuity — the option to receive a lump sum or structured payments at a specific maturity date — clarifies why it is the appropriate choice in this context.