This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: Cardiovascular system, Subject name: Pharmacology
Oral sacubitril is approved for the treatment of 
Select and explain. 
A. Congestive cardiac failure, B. IBS with diarrhea predominance, C. Unstable angina, D. Vitamin K deficiency
A: Congestive cardiac failure
Answer: A: Congestive cardiac failure 
Explanation: Sacubitril is given in combination with valsaan for hea failure. Sacubitril is a prodrug that is activated to sacubitrilat (LBQ657) by de-ethylation esterases. Sacubitrilat inhibits the enzyme neprilysin, which is responsible for the degradation of atrial and brain natriuretic peptide, two blood pressure-lowering peptides that work mainly by reducing blood volume. In addition, neprilysin degrades a variety of peptides including bradykinin, an inflammatory mediator exeing a potent vasodilatory action. Ref: KK Sharma 3rd ed.