Answer:
Option a: all the students at the university.
Step-by-step explanation:
The faculty senate wants to know the proportion of the students that think foreign classes should required for everyone.
The proportion is the statistic, estimated from the sample, to infer the parameter (proportion of the population).
The sample are the 500 students randomly selected.
The population is the total amount of students in the university.
The option (a) is the right answer.