Answer: D. invade public space.
Step-by-step explanation:
Flash mob refers to the group of people who gather in a public place, and then perform for a brief time and then leave after they perform. The performance is typically meant for satire, entertainment, satire, or can be a form of artistic expression. An example of flash mob is people gathering to sing a song, choreography or people involved in a pillow fight.
Some critics of flash mobs believes that flash mobs invade public space and can sometimes be out of control when there are a large number of people who are participating.