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
20 years old Rajesh presence with fever and chronic cough ESR 35 mm sputum cytology is negative for AFB and tuberculin test show in durations of 19 X. 23 mm. The probable diagnosis is – 
Select and explain. 
A. Fungal pneumonia, B. Viral pneumonia, C. Pulmonary T.B., D. Bacterial pneumonia
C: Pulmonary T.B.
Answer: C: Pulmonary T.B. 
Explanation: The history and tuberculin test strongly suggests the diagnosis of T.B.
Do not get confused by negative sputum cytology because negative sputum cytology does not rule out pulmonary tuberculosis.
“Sputum cytology is just a presumptive diagnosis" - Harrison
"The definitive diagnostic of T.B. depends upon the culture of bacteria obtained from respiratory specimen" - Harrison
The presence of induration > 15 mm in size strongly indicates T.B. infection.