You have an exam tomorrow and a friend of yours approaches you at your home for help to understand Newton's law. What will you do?

• A. Ask your mother to tell your friend that you are not at home
• B. Meet your friend and tell him that you don't understand Newton's law to save your time for preparation
• C. Sit with your friend and try to explain Newton's law to him
• D. Tell him that you will let him copy in case Newton's law is asked in the exam