In personam jurisdiction: a. is based on constitutional standards of residence. b. can be based on the subject matter of the case. c. refers to jurisdiction over the parties in a case. d. is only applied in federal courts.

C. refers to jurisdiction over parties in a case

Explanation:

In personam jurisdiction refers to the court's jurisdiction over the parties to a lawsuit or to adjudicate a matter against a party. A court may exercise jurisdiction over a person who resides, maintains connections, or is served notice of legal proceedings in that location.