I think its answer c . Bacteria
Science proceeds by scientific method and use of experimental method. The answer is true because following these steps will get the steps and results you need. There is nothing more to be done. The method is observe a question, make a hypothesis, test the hypothesis with controlled experiment, analyze data. reject or accept hypothesis, and form a conclusion.
Bicarbonate buffer system. Human blood contains large amounts of carbonic acid, which is a weak acid, and bicarbonates, a strong base. If blood pH falls below 6.8 or rises above 7.8, one can become sick or die. This bicarbonate buffer system help maintain blood pH at 7.4. The bicarbonate neutralizes excess acids in the blood while the carbonic acid neutralizes excess bases.
Yes i think so . ;( i really domt have notiing else to type