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: Pediatrics
A five year old child presents with left ventricular hypertrophy and central cyanosis what is the most probable diagnosis – 
Select and explain. 
A. Tricuspid atresia, B. Eisenmenger syndrome, C. Tetrology of Fallot, D. Total anomalous pulmonary venous drainage
A: Tricuspid atresia
Answer: A: Tricuspid atresia 
Explanation: "Left axis deviation and left ventricular hypertrophy are usually present on electrocardiogram distinguishing tricuspid atresia from most other cyanotic heart lesions.

The combination of cyanosis and left axis deviation is highly suggestive of tricuspid atresia."
- Nelson irk p. 1913
Tricuspid atresia 

Congenital absence of tricuspid valve is called tricuspid atresia
	TA has following features : -


Absence of tricuspid valve
Hypoplastic right ventricle with absence of inflow portion of RV


So, blood can not flow directly from right atrium to right ventricle and following associated defect are neccessary for survival : -


For flow of blood from RA to LA Patent foramen ovale or ASD.
For flow of blood from LV to RV --> VSD (VSD is always muscular in tricuspid atresia)


Therefore blood flow in following direction.