Which structure starts at the brain and goes down the back? a) the spinal cord b) the brain stem c) the cerebral cortex d) the limbic system

The spinal cord.

Explanation:

The brain and the spinal cord are attached and the spinal cord from the head goes down to back of the body.

The spinal cord acts as the framework for the backbone and helps in performing various functions of the body. The spinal cord connects the higher centers of the body to the various parts of the body by the help of autonomic and somatic veins of the peripheral nervous system.

carbohydrates: (starches and sugars) composed of carbon, hydrogen, and oxygen.

lipids: (fats, oils, and waxes) are made of carbon and hydrogen atoms.

nucleic acids: contain hydrogen, oxygen, nitrogen, carbon, and phosphorus. they are polymers of nucleotides. a nucleotide has three parts, a 5-carbon sugar, a phosphate     (-po⬇️4) group, and a nitrogenous base.

proteins: made up of nitrogen, carbon, hydrogen, and oxygen. they are polymers of amino acids.

the answer to your question is b