Above is comparing the ratio of students in her class that are wearing the color green to the total number of students in her class. She finds out of 30 students in her class 7 are wearing green. What kind of ratio relationship is she using?

A. Whole relationship
B. Part-to-part relationship
C. Part-to-whole relationship
D. Part relationship

C. Part-to-whole relationship

To determine the kind of ratio relationship the person is using, we need to understand the given information. The person is comparing the number of students wearing green to the total number of students in her class.

In this case, the person is comparing a part (number of students wearing green) to a whole (total number of students in the class). Therefore, the ratio relationship being used is a part-to-whole relationship.

Hence, the correct answer is C. Part-to-whole relationship.