This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: C.V.S, Subject name: Medicine
Single second hea sound is seen in - 
Select and explain. 
A. TOF, B. hypeension, C. Pulmonary oedema, D. MI
A: TOF
Answer: A: TOF 
Explanation: The four components of the tetralogy of Fallot are malaligned VSD,obstruction to RV outflow, aoic override of the VSD, and RVhyperophy due to the RV's response to aoic pressure thelarge VSD. Harrison's principle of internal medicine,20edition,pg no.1554