Churn rate is a term that refers to the:

Select one:

a$.$ rate at which customers leave a product or service.

b$.$ rate at which the demand for a product or service fluctuates with price change.

c$.$ number of movie titles that are difficult to assign reliable user ratings.

d$.$ average number of recommended titles in a user's queue.

e$.$ number of new users that each existing user attracts through word$-$of$-$mouth and social sharing.