Which type of annuity allows contributors to make regular payments?

The choice of a level (fixed) premium annuity as the correct answer is based on how this type of annuity is structured for contributions. A level premium annuity requires the contributor to make regular, predetermined payments over time. These contributions are made at fixed intervals, allowing for consistent investment into the annuity, which can be particularly beneficial for budgeting and long-term financial planning.

In contrast, a single premium annuity requires a one-time lump sum payment at the outset, which does not accommodate regular contributions. A deferred annuity allows for contributions to be made over a period, but it is not specifically tied to fixed payments, as it may include a variety of payment options. A lump sum annuity is similar to a single premium annuity in that it involves a single large payment rather than a series of regular contributions.

Thus, the structure of a level (fixed) premium annuity distinctly supports regular payment contributions, making it the appropriate choice for this question.