In a case where T files a downsloping 14a claim against π after π (Tennessee) sues ∆ (Idaho) and ∆ impleads T (Florida), what is the status of jurisdiction?

Jurisdiction exists due to the same transaction/occurrence, which is the correct rationale. Under the Federal Rules of Civil Procedure, specifically Rule 14, a defendant may implead a third party who is or may be liable to the defendant for all or part of the claim against the defendant. This means T’s claim against π arises from the same set of facts or circumstances involved in the original dispute between π and ∆, establishing a direct connection between the claims.

When there is a common nucleus of operative fact, the courts often find it appropriate to exercise supplemental jurisdiction, as it promotes judicial efficiency by resolving related claims in a single proceeding. Therefore, because T's claim relates closely to the underlying dispute between π and ∆, jurisdiction is established under this broader umbrella of the same transaction or occurrence, even considering diversity and the states involved (Tennessee, Idaho, and Florida).

The other options don't accurately reflect the principles of jurisdiction as they pertain to 14a claims, where the relationship between the claims is critical for determining jurisdiction.