For each of the following, indicate whether you would use a pie, line, or bar chart, and why: The proportion of freshmen, sophomores, juniors, and...

1.    For each of the following, indicate whether you would use a pie, line, or bar chart, and why:

a.    The proportion of freshmen, sophomores, juniors, and seniors in a particular university

b.    Change in GPA over four semesters

c.    Number of applicants for four different jobs

d.    Reaction time to different stimuli

e.    Number of scores in each of 10 categories