If the price a consumer pays for a product is equal to a consumer's willingness to pay, then the consumer surplus relevant to that purchase
a. zero.
b. negative, and the consumer would not purchase the product.
c. positive, and the consumer would purchase the product.
d. there is not enough information given to answer this question.

a. zero.

Explanation:

Willingness to pay is the highest price a consumer is willing to pay for a good or service.

Consumer surplus is the difference between the willingness to pay and the price of a good or service.

If willingness to pay is equal to price, consumer surplus is zero.

If willingness to pay is greater than price, consumer surplus is postive and the consumer would purchase the product.

If willingness to pay is less than price, consumer surplus is negative and the consumer would not purchase the product.