I think it is the 3rd one because health problems at older age.
Answer:
When calcium concentration increases during depolarization, it shifts the conformation of troponin and tropomyosin, and actin is able to associate with myosin. As calcium is taken up again by the sarcoplasmic reticulum the muscle cell relaxes.
The possibility to answer is C.
B.) Soda pop is the solution among them........
Answer: they allow air to enter lungs and also permits air into the body
Explanation:
