Questions: What is the correct definition of voluntary muscles? A. Muscles that exist deeper within the body, underneath superficial muscles. B. Muscles that contract without conscious control. C. Muscles that occur close to the skin, and rest on top of other, deeper muscles. D. Muscles that connect at either or both ends of a bone and move parts of the skeleton.

The answer is D: Muscles that connect at either or both ends of a bone and move parts of the skeleton.

Explanation for each option:

A. Muscles that exist deeper within the body, underneath superficial muscles.

• This option describes the location of muscles rather than their function or control. It does not specifically define voluntary muscles.

B. Muscles that contract without conscious control.

• This describes involuntary muscles, such as those found in the heart and digestive system, which operate without conscious effort.

C. Muscles that occur close to the skin, and rest on top of other, deeper muscles.

• This option describes the position of muscles relative to the skin but does not define voluntary muscles.

D. Muscles that connect at either or both ends of a bone and move parts of the skeleton.

• This is the correct definition of voluntary muscles, also known as skeletal muscles, which are under conscious control and are responsible for moving the skeleton.

In summary, voluntary muscles are those that are consciously controlled and are primarily responsible for skeletal movement.