If one tank treats 14 acres and the application rate is 1.5 pints per acre, how many pints are needed for the tank?

To determine how many pints are needed for the tank, you start by calculating the total amount of product required for the entire area that one tank can treat. In this case, one tank can treat 14 acres, and the application rate is 1.5 pints per acre.

To find the total pints needed, multiply the number of acres by the application rate:

14 acres x 1.5 pints per acre = 21 pints.

This calculation shows that for one tank treating 14 acres at an application rate of 1.5 pints per acre, you will need a total of 21 pints. This amount directly corresponds to the choice given, making it the correct answer.