What is the type of muscle contraction that occurs when the muscle contracts and shortens? a. Isometric. b. Involuntary. c. Incidental. d. Volunt...

The correct answer is d. Voluntary. When a muscle contracts and shortens, it is referred to as a voluntary muscle contraction. Isometric contraction refers to when the muscle contracts but does not change in length, while involuntary and incidental are not specific types of muscle contractions. None of the above is not the correct answer in this case.