Johnny wants to know how many students in his school enjoy watching science programs on TV. He poses this question to all 26 students in his science class and finds that 75% of his classmates enjoy watching science programs on TV. He claims that 75% of the school's student population would be expected to enjoy watching science programs on TV. Is Johnny making a valid inference about this population? (5 points)

a
Yes, it is a valid inference because his classmates make up a random sample of the students in the school

b
Yes, it is a valid inference because he asked all 26 students in his science class

c
No, it is not a valid inference because he asked all 26 students in his science class instead of taking a sample from his math class

d
No, it is not a valid inference because his classmates do not make up a random sample of the students in the school