The Hershey and Chase experiment concluded the same by labeling the DNA of the parents with phosphorous and found out that the DNA of the offspring also bear phospho- labeled DNA, which established the fact that DNA is the heritable information source. So, your answer is B.
They need more nutrients/food than their bodies can absorb through the skin and they can eat more by actually consuming physically.
The pulmonary circuit transports blood to the lungs. The blood is oxygenated there and then carried back to the heart. Gaseous exchange happens in the lungs:
Carbon dioxide diffuses from the blood into the air in the alveoli.