Messages are transmitted from your spinal cord to muscles in your hands by the nervous system

Sympathetic Nervous system

Explanation:

The sympathetic nervous system transfers the messages from the brain to the muscles of hand through the spinal cord.

The sympathetic nerves starts from the inside of the vertebral column towards the middle of the spinal cord in the intermediolateral cell column.

This nervous system is responsible for carrying out the messages from the muscles from the spinal cord to the hands.

explanation:

b,bacteria convert nitrates

into nitrogen gas.

d,plants and animals take in

and use nitrogen compounds.

e,bacteria break down waste    

products and return nitrogen  

to the soil.

a,bacteria convert atmospheric

nitrogen to ammonia.

c,bacteria convert ammonia

to nitrites and nitrates.

the correct answer, according to e2020, is the second choice there is an occluded front in region a and a cold front in region b.