Select the situation in which one quantity is changing at a constant rate in relation to another quantity. a. claire earns 2% interest on her retirement fund every month. b. the production of wool at a factory doubles every 2 years. c. the value of a car is 0.8 times the value of the car the previous year. d. emma read 15 pages of her novel each hour.

D. is the answer to this question

D. Emma read 15 pages of her novel each hour.

Step-by-step explanation:

Earning 2% interest means the amount of interest, in terms of dollar amounts, changes every year.  This is not a constant rate of change.

Doubling the production means the amount of extra production changes every year.  This is not a constant rate of change.

A value of 0.8 times the value the previous year means the amount of decrease changes every year.  This is not a constant rate of change.

Reading 15 pages of a novel every hour means that every hour, the number of additional pages read is the same.  This is a constant rate of change.