Informal organization refers to people working together or in contact with each other, based on feelings, personalities, hobbies on the same basis, the formation of a number of groups. These groups are not subject to the administrative and administrative hierarchy of formal organizations, and there is no clearly defined formal structure, but within them to form a number of specific relationship structures, naturally emerging their own leaders, forming some unwritten codes of conduct and norms.
According to the above definition, which of the following options refers to a group of people who belong to an informal organization?
Xiao Zhang is the head of the school's student union, after her introduction, several students participated in the performance