Which of the following variables is considered a discrete variable?

Which of the following variables is considered a discrete variable?

Select one:

a. Amount of water in the Pacific Ocean.

b. Money spent on gasoline during a week. 

c. Grade point average (GPA) of students during 2016.

d. Number of customers that visited a shopping mall during the summer months.

Suppose that you have a dataset capturing the job title of 1,000 people. Which of the following is the best way to represent that dataset graphically?

Select one:

a. Boxplot

b. Bar chart

c. Histogram

d. Stem-and-leaf