The brain and spinal cord work together so the body can receive signals and react to the environment. what is the spinal cord?

a cell
a tissue
an organ
an organ system

c.) an organ

Explanation:

this is the right answer on edg 2020

hope this helps!!!

i believe the correct answer from the choices listed above is the first option. the scientists need to look at the   validity of data, claims, hypotheses, and observations before  developing an argument. they base their arguments on facts that are present and they make sure they have proofs. 

explanation:

answer; polycythemia is the correct answer;