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: Pathology
Route of infection in Tubercular Pyelonephritis - 
Select and explain. 
A. Ascending, B. Descending, C. Haemotogenous, D. Airborne
C: Haemotogenous
Answer: C: Haemotogenous 
Explanation: None