To be honest, I don't really understand what your talking about, but I think the answer is cell respiration.
Answer:
D) Bathroom
Explanation:
Bathrooms are commonly close to the center of the house, and don't have windows, which makes them incredibly safe in event of tornadoes, leaving the only better places storm shelters, or basements.
The answer would be offspring. Why? When a sperm and an egg meets, it creates a zygote.
Those two are the muscular system and the excretory system because you use your muscles to push up and down and your excretory system produces the sweat you use while doing them