Answer:A
Explanation:it’s being change by a mixture of substances put together
The true descriptions regarding muscles are; Cardiac muscles and skeletal muscles are striated, heart (cardiac) and digestive (smooth) muscles are involuntary muscles, cardiac muscles work to pump blood. Skeletal muscles are the muscles that attach to the bones and their main function i contracting to facilitate movement of our skeletons. Smooth muscle are found in walls of hollow organs such as the stomach and are stimulated by involuntary action. While the cardiac muscles are found solely in the walls of the heart, they are highly specialized and under the control of of the autonomic nervous system.
The answer is letter b. adaptation. Adaptation occurs when living organisms adapt to their surroundings or environment over a long period of time. In this case, Dark Furred Squirrels were abundant, since squirrels adapted to the dark shady area they have lived and adapted into a dark furred one, which allowed it to be more common due to adaptation.