Which of the following statements is true about permissive joinder?

Permissive joinder refers to the ability of a party to join multiple claims or parties in a single lawsuit under certain conditions in order to promote judicial efficiency and convenience. The correct statement highlights that permissive joinder allows for the addition of claims that do not have to be essential to each other, meaning that parties can join claims based on a common question of law or fact, or in situations where it furthers the interests of justice.

This flexibility is beneficial as it helps to prevent multiple lawsuits and allows related claims to be settled in one proceeding. Courts encourage permissive joinder as it can lead to a more streamlined judicial process and could reduce the burden on the court system.

In contrast, the other statements mischaracterize the concept of permissive joinder by implying a level of obligation or restriction that doesn't exist within this procedural framework. For instance, the notion that all claims must be joined or that participation is mandatory for all parties overlooks the discretionary nature of permissive joinder. Additionally, the assertion that permissive joinder is not allowed in most jurisdictions is inaccurate, as it is a recognized practice under the Federal Rules of Civil Procedure and in many state jurisdictions.