State which graph (Pareto chart, time series graph, or pie graph) would most appropriately represent the given situation.
a. The number of students enrolled at a local college for each year during the last 5 years.
b. The budget for the student activities department at a certain college for a specific year.
c. The means of transportation the students use to get to school.
d. The percentage of votes each of the four candidates received in the last election.
e. The record temperatures of a city for the last 30 years.
f. The frequency of each type of crime committed in a city during the year.