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: Medicine
True regarding presentation of Primary TB is: 
Select and explain. 
A. Bilateral pleural effusion with negative tuberculin test, B. Unilateral hilar lymphadenopathy, C. Sustained chronic pyrexia, D. B/L pleural effusion with positive tuberculin test
B: Unilateral hilar lymphadenopathy
Answer: B: Unilateral hilar lymphadenopathy 
Explanation: TB in young children is almost invariably accompanied by hilar or paratracheal lymphadenopathy due to the spread of bacilli from the lung parenchyma through lymphatic vessels.