What is the difference between simple and compound interest rates

see below

Explanation:

Simple interest is a method of calculating gains or yields from savings, deposits, or credit. In simple interest, the interest earned is a constant figure throughout the life of an investment or loan. Simple interest is usually expressed as a percentage, called the interest rate. It is calculated by multiplying the interest rate by the principal amount and by the time. The interest rate quoted applies for a year.

Unlike simple interest, interest earned in compound interest increases every year. Compounding interest refers to the practice of adding interest earned to the principal amount. An increase in the principal amount results in an increase in the interest earned. Due to the compounding effect, a compound interest-earning account will yield more interest than a simple interest-earning account.

answer; (a) calling people who have not shown interest in the product and asking them to buy it;

b is the correct answer