Which of the following is NOT a form of liability?

Voluntary liability is not recognized as a formal category of liability in legal contexts. The concept of liability typically encompasses obligations that arise from a duty to act in a certain manner or due to legal obligations imposed by statutes, contracts, or common law.

Absolute liability, strict liability, and vicarious liability each represent distinct forms of liability where individuals or entities can be held responsible for damages or injuries under specific conditions without the need to prove negligence or fault.

Absolute liability requires no proof of negligence; simply engaging in certain activities (like using hazardous materials) can result in liability for any resulting damages. Strict liability similarly holds parties responsible for damages resulting from their actions, even if they were not negligent, typically in cases involving inherently dangerous activities. Vicarious liability allows one party (usually an employer) to be held responsible for the negligent actions of another (usually an employee) carried out in the course of their employment.

In contrast, the term "voluntary liability" does not carry the same established legal meaning and is not classified among these recognized liability types, making it the correct answer.