I would say it is A) b/c you were listening you just didnt here him/her clearly
Answer;
D. Products are not proven to increase immune health, but research shows that a healthy lifestyle will benefit your immune system.
Explanation;
A healthy lifestyle helps keep the immune system happy and healthy. Factors such as stress, bad eating habits, lack of sleep, and unhealthy lifestyle habits can weaken the immune system. From research healthy lifestyle is key in boosting the immune system. Products claiming to boost the immune health have not been proven to do so.
Answer: It's called an Extension movement
Explanation:
One of the example is the joint in your elbow. If you straighten your arm, it will make the angle of the joint in your elbow to increase and create an extension movement
Another example is the joint in your hips