Answer:
The answer is A, open systems!!
Explanation:
all systems on earth are open, except for the earth itself.
A rock.
It could not get cancer because it is not a living organism. Hope this helps you.
The deficiency of vitamin d may lead to cardiovascular disease. Heart conditions, such as those that affect your heart's muscle, valves or rhythm, also are considered forms of heart disease. This is usually referred to conditions that there is a narrowing or blocking of blood vessels that can become a heart attack, chest pain (angina) or stroke.
