If a company sells one of its products for $9.99 rather than $10, it is using:

The business is using the odd even pricing. This is a psychological pricing technique grounded on the belief that fixed prices or price ranges are more attractive to buyers. This technique encompasses setting an amount in odd numbers (just under round even numbers) such as $49.95 rather than $50.00.

answer (b); /// a method of measuring the opinions of a large group of people by selecting a subset of the larger group, asking them a set of questions and then generalizing those responses;