Section 34 IPC (common intention) requires active participation in the criminal act. Section 149 IPC (vicarious liability of unlawful assembly) punishes all members of the assembly even if they only had passive membership. Option C correctly captures this key distinction. Option A is wrong (Section 34 requires minimum 2 persons, not 5). Option B is incorrect (Section 149 creates substantive vicarious liability, not just evidentiary rule).