Which of the following is a characteristic of a life annuity?

A life annuity is designed to provide guaranteed payments for the lifetime of the annuitant. This characteristic is what makes it distinct from other financial products and types of annuities. The primary purpose of a life annuity is to offer financial security by ensuring that the individual will receive a stream of income for as long as they live, regardless of how long that may be. This feature addresses longevity risk, which is the risk of outliving one's savings.

The other options, while applicable to different types of annuities or investments, do not pertain to the defining feature of a life annuity. Payment for a fixed duration only refers to fixed-period annuities, which do not offer the same guarantees as life annuities. Flexibility in payouts and investment options typically describe other financial instruments like variable annuities or other investment products, but they do not align with the guaranteed nature of life annuity payments.