Under which installments option does the annuitant select the amount of each payment?

The fixed amount option allows the annuitant to choose a specific dollar amount for each payment they receive. This means that the annuitant can determine how much money they want to receive consistently, which can be beneficial for budgeting and planning purposes. The payments will continue until the total account balance is depleted, which can provide the annuitant with a reliable income stream.

In contrast, the variable amount option would involve payments that can fluctuate, usually based on investment performance, which may not provide the stability that the fixed amount option offers. The lifetime option focuses on providing payments for the duration of the annuitant's life, which does not allow them to specify the payment amount, as it would depend on their life expectancy and the terms of the contract. The equal payments option also does not grant the annuitant discretion in selecting their payment amount, as it typically refers to a constant distribution not influenced by individual choice. Thus, the fixed amount option is the correct choice since it uniquely empowers the annuitant to determine their payment size directly.