Suppose that at the end of a quarter at Drexel, the undergraduate advising office wants to examine the grades that students got in courses. They take a random sample of 1000 students that completed a course with a grade (i. e., they are not counting withdrawals, incompletes, etc.). Students in the sample either passed the class with a grade of A, B, C or D or they failed the class, receiving an F. In that sample, 760 of the 1000 students passed the class with a grade of A or B. Which of the following statements are true? a. The complement of this event is a student passing with a grade of C or D and the probability is 24%
b. The complement of this event is a student passing with a grade of C or D and the probability is unknown
c. The complement of this event is a student passing with a grade of C or D or failing with a grade of F and the probability is 24%
d. The complement of this event is a student passing with a grade of C or D or failing with a grade of F and the probability is unknown