Ultrahazardous activities: a. are defined by federal statutes. b. are subject to strict liability. c. only create liability where the defendant fails to act as a reasonable person. d. only create liability when the defendant fails to exercise utmost care.

b. Are subject to Strict Liability

Explanation: Ultrahazardous activity or inherently dangerous Activity is a common law of torts. And it is so inherently dangerous that a person engaged in such an activity can be held strictly liable for injuries his/her actions caused to another person, even he/she engaged took every reasonable precaution to prevent injuries to other people.

Examples off ultrahazardous activity: So many activities are commonly recognized as being inherently hazardous and dangerous and those who engage in them are subject to strict liability.

Examples includes:

Transportation, storage, and use of dynamite and other explosives, radioactive materials and certain hazardous chemicals

Keeping of animals that are not normally domesticated in that area(wild animal),

Keeping of domesticated animals that have a every knows has dangerous behavior like keeping a dog that attacks people.

If you are injured by one of these inherently hazardous activities while trespassing on the property of the person engaged in the activity, you are not permitted to sue the person under a strict liability theory. But you must prove that the property owner was negligent. But if you are attacked or injured in the street, then you can sue the person and he is to face judgement for his ultrahazardous activities or actions.