I believe that the correct answer is D.)Animal Species
Animals reproduce , breed , and affect the agriculture.
Look up the word agriculture , you will see how my answer makes more sense.
My reason being is mainly because everything basically lives off of animals and if the are affected by anything and in any way start to decrease , the population will also.
I really hope that this helps you out a lot.
He instituted military mobilization
No se xd
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Be specific
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Explicar
Galen's area of expertise were in pharmacology, surgery and anatomy. He was also known by the name of "father of experimental physiology". He was not only a biologist but also a physician. He was born in 129 AD and died on 219 AD. He was very famous for making the first experimental medicine.