Central Nervous System (CNS) (Brain and Spinal Cord)
Peripheral Nervous System (PNS) (Nerves to and form CNS)
<span>Assuming that this is referring to the same list of options that was posted before with this question, the best option from the list would be the ones having to do with system references. </span>
Answer:
B. Organ system
Explanation:
Cells are the smallest level of organization. They make tissues and tissues make organs like heart and lungs. Organs make organ systems which are the highest level of organization such as respiratory system which includes organs like lungs etc.
The atomic number of an element is the number of protons in the nucleus of an atom of that element.
Atoms with the same number of protons, but a different number of neutrons are called isotopes.
