The answer is between A and C.
-DNA is the blueprint for proteins, which play many roles in the body. PROTEINS play many roles in the body and determine many traits. The section of DNA that codes for a specific trait is called a GENE. In fruit flies, straight wings are dominant and curly wings are recessive.
The warm air will rise because cold air is heavier than warm air.
Unoxygenated blood from veins enters the right atrium then it goes down to the right ventricle then out through the pulmonary artery to the lungs where it becomes oxygenated blood which then enters the heart through the pulmonary veins and it goes to the left atrium and then is pumped down to the left ventricle and out through the aorta to the arteries where it travels to different organs and becomes deoxygenated and then the cycle repeats itself.