Select the correct answer. Mateo teaches a continuing education class at the library on Tuesday nights. He estimates that 75% of his students are satisfied or very satisfied with the class.

Last week, he asked a random sample of students to take a survey on their experience in the class. However, the results showed that only 70% indicated that they are satisfied or very satisfied with the class. He decides to randomly survey more of his students. How will Mateo know whether his model is valid or not?

A.
It is valid if the result from all the surveys and the model get closer together.
B.
It is impossible to determine whether the model is valid.
C.
It is valid if the result from all the surveys and the model stay the same.
D.
It is valid if the result from all the surveys and the model get farther apart.