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
Differential cyanosis is seen in – 
Select and explain. 
A. TGV, B. TAPVC, C. PDA, D. VSD
C: PDA
Answer: C: PDA 
Explanation: Differential cyanosis 

When one extremity is pink and the other extremity is cyanotic, it is referred to as differential cyanosis.

Causes of differential cyanosis