A team of employees at a restaurant franchise uses a frequency table to show the number of items purchased in each of 150 transactions. If they want to create a histogram from these data, what values should go on the x-axis?

5 21

4 35

3 58

2 22

1 14

a. The values for the number of items variable

b. The midpoint of the frequencies

c. The frequency

d. The average number of items