This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: Immunology, Subject name: Microbiology
Primary complex of TB is known as: 
Select and explain. 
A. Ranke's complex, B. Ghon's complex, C. Assman focus, D. Simon's focus
B: Ghon's complex
Answer: B: Ghon's complex 
Explanation: Ans. B. Ghon's complexPrimary focus - Ghon's focus + lymph nodes - Ghon's primary complex + calcification - Ranke's complex. Reactivation secondary TB - Simon's focus + calcification - Assman's focus