Kari, a biologist, is getting ready for a new study of tropical fish. She needs to fill the tank with precisely 5 gallons of water. She uses a quart container. 8 fluid ounces = 1 cup. 2 cups = 1 pint. 2 pints = 1 quart. 4 quarts = 1 gallon.

How many times will Kari have to fill the container to make 5 gallons?
10 times
15 times
20 times
25 times