Final answer:
Ethics is the branch of philosophy that deals with the nature of values or the good, and includes the valuation of physical activity.
Step-by-step explanation:
The branch of philosophy that looks at the nature of values or the good, including why and how we value physical activity, is known as ethics. Ethics examines questions such as what is considered the good life, what actions are morally right, and the nature of virtue and well-being. It also explores the ethical obligations of individuals within a society and the judgments we make about what ought to be. Therefore, the correct answer to the student's question is c) Ethics.