The answer would be the second option. The best reason for doing more background research after making an observation and before forming a hypothesis is to prevent making the same mistakes made in a prior experiment. It is to make sure that you are able to see the problems of a research and make an experimental design that will minimize the errors.
        
                    
             
        
        
        
The answer is e. Calcitonin, Aldosterone and Atrial natriuretic peptide.
 The calcitonin is a hormone secreted by the thyroid gland. Calcitonin is involved in the regulation of the levels of calcium and phosphate in the blood. Aldosterone is a hormone secreted by the adrenal gland.  It is essential for maintaining the store of sodium in the kidney, salivary glands, sweat glands and colon. Atrial natriuretic peptide (ANP) or Atrial natriuretic factor (ANF) is a peptide hormone synthesized, and secreted by cardiac muscle cells in the  heart. ANP is involved in the regulation of sodium levels in the cells of the heart.
 
        
             
        
        
        
The ribosomal RNA studies that led to the division of prokaryotic organisms into the bacteria and the archaea were begun by Woese. 
Ribosomal RNA makes the maximum portion of RNA in the cells. However, it is not translated into proteins. But it plays a major role in the translation of m-RNA. They are responsible for deducing the order of the amino acid sequence and linking the amino acids together to form the polypeptide. 
Archaea are a group of organisms that are similar to bacteria, yet have evolutionary differences. They are found in extreme locations like hot spring, salty water bodies, or areas where methane if formed. Therefore, they are also known as extremophiles.
To know more about archaea, here
brainly.com/question/1475001
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 Red blood cells exchange carbon dioxide for oxygen