Academic Research into What a Team 'Is' Can Assist Understanding

Academic research into what a team 'is' can assist understanding into what the nature is of the processes occurring between individuals operating in such structures.
Conceptually how does Schein (1994) specifically determine the nature of a team?

A) A team is 'a group of people who are committed to the attainment of a common objective, who work well together and enjoy doing so, and who produce high quality results'.
B) Teams often exist within a larger organizational context and who are not seen by others as a social entity, who are dependent because the tasks they perform are as individual members of a group.
C) The team is 'any number of people who interact with one another, are psychologically aware of one another, and perceive themselves
To be a group'.
D) The team is 'any number of people who conflict with one another, are psychologically aware of one another, and perceive themselves
To as an individual'.