The histogram shows the number of vacation days taken by employees in the past year. based on the histogram, which statement is true?

a. four employees took 20 vacation days in the past year.

b. four employees took 25 vacation days in the past year.

c. four employees took between 20 and 25 vacation days in the past year.

d. between 20 and 25 employees took four vacation days in the past year.