The correct answer is C. Precipitating factors
Explanation:
In collective behavior, "precipitating factors" refers to one of the factors or triggers of collective behaviors or those factors or behavior from individuals that represent a cause for a collective response and that usually linked to a dramatic event that led to others. This is the case of a "boy throwing rocks during a demonstration" because this action becomes a factor for a specific response from a collectivity but during this stage the collectivity has not mobilized for action or act to achieve a purpose; additionally as part of precipitating factors this situation is linked to a dramatical event that can create further actions from a group of people.
Answer: C. Mental channel :)
