Mrs. Suyata assigned her third- and fourth-period math classes into two study groups. Which describes the variables in the two-way table? Group Assignments

Group 1
Group 2
Total
3rd Period
18
14
32
4th Period
15
17
32
Total
33
31
64
period number and study group number
period number and group 1
study group number and period 3
study group number and total