For diversity jurisdiction in a class action, which statement is correct regarding citizenship?

• A. Diversity is determined by the citizenship of all named class members
• B. Diversity is determined by the citizenship of the named plaintiff(s) and named defendant(s) only
• C. Diversity is irrelevant in federal court for class actions
• D. Diversity is determined by the jurisdiction where the class action was filed

Answer: (B)

Diversity for a class action in federal court is determined by the citizenship of the named plaintiffs and the named defendants. The class members themselves, though numerous, are represented by those named parties for jurisdictional purposes, so federal jurisdiction relies on whether the named plaintiffs are citizens of different states from the named defendants (complete diversity). The citizenship of unnamed class members does not affect the court’s subject-matter jurisdiction, though it can matter for other issues like members’ claims or remedies. If any named plaintiff shares a state citizenship with any defendant, there is no complete diversity and federal jurisdiction under Rule 23 would be lacking. The other statements misstate how jurisdiction is established or ignore the role of the named parties. (Note: CAFA introduces a different minimal-diversity framework in many class actions, but the traditional rule is as described.)