A car manufacturer stated in its advertising that the gas mileage for its hybrids will be greater than 40 mpg on average. A consumer agency tested a sampling of the hybrids under a variety of conditions. Based on these tests, the agency concluded that the manufacturer was justified in making this claim. The process described is an example of: ___________

a. Both B and C are correct.
b. descriptive statistics.
c. statistical inference.
d. hypothesis testing.