This is a test of commonsense with single/multi-choices. Complete the next sentence:

How to study the functions of motor neurons of the nervous system of humans
Study the functions of motor neurons in humans.
This article will discuss in this article motor neurons of the nervous system in humans due to its clinical significance in the practice of the neurological sciences of clinical medicine. Motor neurons are a class of cells of the nervous system in all living systems including human individuals.

Choices: [i] These cells create and maintain areas that are interlinked with motor neurons. Study the functions of motor neurons of the body of humans. [ii] Neurons of the nervous system in humans are classified according to their function into three main types. One is sensory type of neurons and the other is motor type of neurons and the third is called integrative type of neurons. [iii] Therefore systematic study is recommended and driven by this career focus. Take the fundamentals of motor neurons a few times. [iv] Motor neurons are also known as neurosystems in humans due to their neurological role in inducing the functioning of the nervous system. Take part in the study of the function of motor neurons in humans.
The answer is:
[ii]