Answer:
I would say c.
the methods of sampling is neither biased nor unbiased
There are different kinds of persons and one type is composed of those who work well alone while other would prefer to work in the group. If the group is large enough so that it is just conducive for learning then, it will be helpful to the dynamics. However, if it is very big that it is no longer healthy then, it would be better to divide further the group.
The life of guy Montag, a fireman in a near future dystopia to make an argument against mindless conformity and blissful ignorance