Answer:
The correct anwser is D. Signals inside the spinal cord
Explanation:
hope this helps :)
DNA is the genetic composition of the cells in the human body, think of it as the coding for a computer but for cells. These carry your genetic composition (blue eyes, Brown hair, tall, short blah blah blah) and traits like smart, funny, shy.
Hope that helps.
He based his hypothesis on a statement made by a dairymaid.