Refer to the following frequency distribution of days absent during a calendar year by employees of a manufacturing company:

Days Absent Number of employees

0 up to 3 60
3 up to 6 31
6 up to 9 14
9 up to 12 6
12 up to 15 2

How many employees were absent six or more days?

a. 2
b. 29
c. 14
d.31