Briefly explain the purpose of a variable annuity and the financial theory that underlies it.

Question:

Briefly explain the purpose of a variable and the financial theory that underlies it.
Annuity
An annuity is a series of equal payment made at equal intervals during a period of time. In other words annuity is a contract between insurer and insurance company in which insurer make a lump-sum payment or a series of payment and, in return,...