Morgan's math teacher gives weekly quizzes during class. All of the items on the quizzes are designed to assess students understanding of crucial math concepts, and Morgan is a good student who studies consistently for the class. However, her scores fluctuate a great deal. Some weeks she gets every question right, and some weeks she gets more than half wrong. Given these inconsistent scores, you might wonder whether the quizzes are _______.a. reliable
b. statistically significant
c. generalizable
d. valid