A type of security payment in which payments are made at equal intervals of time and each payment amount is same is classified as

fixed interval investment
fixed payment investment
annuity
lump sum amount

The correct answer is C. Annuity.

An annuity is a series of equal payments made at regular intervals for a fixed period of time. The payments can be made monthly, quarterly, semi-annually, or annually. Annuities are often used to provide income in retirement.

A fixed interval investment is an investment in which the amount invested is the same each time. For example, you might invest $100 each month into a fixed interval investment.

A fixed payment investment is an investment in which the amount paid out is the same each time. For example, you might receive $100 each month from a fixed payment investment.

A lump sum amount is a single payment that is made at one time. For example, you might receive a lump sum payment of $10,000 from an inheritance.