The correct answer is 2. Students from different schools want to talk about a community project
Explanation
Online discussion groups are online sites where people discuss or hold conversation about specific topics through messages, as these are online groups they rely on Internet connection and because of this any person with access to internet connection that belongs to the group can participate in the discussions without the limits of a specific time or place; this means members do not need to be in the same place or set a specific time to talk about the community project, which is something necessary for students from different schools as it might be difficult for them to have a face to face meeting, which is quite possible in the other cases.
