Question

the heart muscle is an example of
skeletal muscle.
smooth muscle.
involuntary muscle.
voluntary muscle.

Explanation:

Skeletal muscles are voluntary and attached to bones. Smooth muscles are involuntary and found in organs like the intestines. Voluntary muscles are under conscious control. The heart muscle (cardiac muscle) is involuntary as its contractions are not consciously controlled. So the heart muscle is an example of involuntary muscle.

Answer:

C. involuntary muscle.