This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: None, Subject name: Pharmacology
Enalapril increases the level of: 
Select and explain. 
A. Interferon, B. Growth factors, C. Bradykinin, D. All of the above
C: Bradykinin
Answer: C: Bradykinin 
Explanation: Enalapril is an ACE inhibitor and the adverse effect profile of all ACE inhibitors is similar. One side effect is cough in the patients taking ACE inhibitor.
A persistent brassy cough occurs  in 10- 16% patients within 1- 8  weeks, often requires discontinuation of the drug-subsides 4- 6 days thereafter. It is not dose related and appears to be  caused by inhibition of bradykinin/substance P breakdown (which leads to increase in levels of Bradykinin)  in the lungs of susceptible individuals.
Reference: Essentials of Medical Pharmacology Eighth Edition KD  TRIPATHI  page no 531