What can be a feature of annuities?

Annuities typically allow for interest rates that can either be fixed or variable, which is a defining feature of these financial products. A fixed interest rate means that the returns are predictable and stable over the life of the annuity, while a variable interest rate can fluctuate based on the performance of underlying investments, offering the potential for higher returns but also greater risk.

In contrast, the other choices do not accurately represent standard features of annuities. While some annuities may allow for additional contributions, this is not universally true and depends on the specific type of annuity. Many annuities also do not provide unlimited access to investment funds; there are often restrictions and penalties for early withdrawals. Lastly, early withdrawal from an annuity typically incurs penalties, particularly in the initial years, to discourage the premature encashment of the contract. Thus, the feature that the interest rate can be either fixed or variable stands out as a hallmark of how annuities operate.