The correct answer is C) Support system
Step-by-step explanation:
A support system refers to an individual group of people or other entity that provides support to another person, this means the support system helps the individual to keep focused on something or achieve a certain purpose. In the case presented, Kara's sister is the support system of Kara because she is helping her to be part of the exercise program by exercising with her. Also, she helps Kara to avoid abandoning the program and keep focus by reminding her about her progress. Thus, another name for Kara's sister is "support system".