There are four classes of third graders at Woodbury Elementary School. One class has 24 students, one has 26 students, another has 31 students and the last has 22 students. The principal would like to split the third grade population into two groups for lunch period. Which expression represents the separation of the third grade into
two groups?
A. 2(24 +26 +31 +22)

B. 24+26+31+22
2
C. (24 +26) - (31 +22)

D. 2 24 +26+31 +22