Jejunum if what i thought of
While doing exercise, one can control skeletal muscles only.
The body has three kinds of muscles, that is, skeletal muscle, cardiac muscle, and smooth muscle. The skeletal muscles are linked with the bones of the skeleton, that is why these are under control and are known as voluntary muscles.
On the other hand, the smooth muscles like skeletal muscle can never be under control. These muscles helps in pushing substances, like blood or food through organs. The cardiac muscle is also an involuntary muscle, which is found only in the heart. These muscles helps in contraction of the heart and can never be controlled.
Hi,
The answer should be letter B, as H2O is a compound made of two different elements in a definite proportion.
Answer: look at the picture
Explanation: Hope this help :D