Who may file a Rule 12(b)(6) motion?

• A. The court
• B. A defendant
• C. A plaintiff
• D. A mediator

Answer: (B)

Rule 12(b)(6) is a pleading-stage defense used to challenge whether the plaintiff's complaint states a claim upon which relief can be granted. The motion is brought by the party defending the suit—the defendant. The court itself can raise the issue on its own (sua sponte), but a Rule 12(b)(6) motion is filed by the defendant in response to the complaint. A plaintiff doesn’t file this motion to dismiss; mediators aren’t parties to the case and don’t file motions.