Answer:
The circulatory system
Explanation:
The heart, veins and arteries works together to service the cells of the body
He was one of the first scientists to understand that new scientific information comes from repeated experiments, and one of the first to incorporate math and science together. He revolutionized the method research was obtained by scientists.
The answer is D
I hoped this helped
A.) Cytosine bases
But also technically C, although that is a bit trivial.