Final answer:
A parameter is the data used by a function to produce a result. In this case, the survey conducted by the U.S. federal government uses the percentage of high school seniors planning to attend a four-year college or university in the following year as the parameter.
Step-by-step explanation:
The correct answer is b. parameter.
A parameter is the data used by a function to produce a result. In this case, the function is the survey conducted by the U.S. federal government, and the data used is the percentage of high school seniors planning to attend a four-year college or university in the following year, which is 50 percent.