A Statistics Instructor Wishes to Know the Average Age (In

A Statistics instructor wishes to know the average age (in month) of his 200 students.He decides to choose 25 students from the class and ask them for their age.All 200 names are put in a hat and 25 names are then chosen at random (without replacement) .The average age of the students chosen is observed to be 231 months.In this example,"200" is known as what?

A) The sample
B) A census
C) The population
D) The population size
E) The sample size