A 65 year old male with a history of congestive heart failure and severe chronic obstructive pulmonary disease complains of increasing dyspnea on exertion, lower extremity edema, paroxysmal nocturnal dyspnea, and orthopnea. His ejection fraction is noted to be 15%. Physical examination reveals an S3 heart sound, pulmonary rales, and lower extremity pitting edema. Which of the following elevates in the serum with congestive heart failure, reduces preload and afterload and causes diuresis?
B. Carbon dioxide
C. B-type naturitic peptide