According to Research,social Groups Tend to Range in Size from Two

According to research,social groups tend to range in size from two or three members to several dozen members.Why is this?

A) If groups were larger it would be impossible to interact with other members.
B) If a group becomes too large conflict within the group becomes unavoidable.
C) It would be difficult for members to find more people who are similar to them.
D) It is too difficult to arrive at normative consensus when groups grow too large.
E) The larger the social group, the greater the likelihood of destructive conflict.