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: Physiology
Two point threshold test, tests the integrity of: 
Select and explain. 
A. Anterior spinothalamic tract, B. Lateral coicospinal tract, C. Lateral spinothalamic tract, D. Dorsal column
D: Dorsal column
Answer: D: Dorsal column 
Explanation: Dorsal column (medial lemniscal system): Fibres mediating fine touch, fine pressure, two point discrimination, proprioception, joint position sense and vibration ascends in the dorsal column. Ref: Ganong's Review of medical physiology, 22 Edition, Page 138.