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: Unknown
Which body part has maximum representation in CNS? 
Select and explain. 
A. Urinary Bladder, B. Lower limb, C. Abdomen, D. Thumb
D: Thumb
Answer: D: Thumb 
Explanation: Somatosensory cortical areas
Primary- Post central gyrus
Association area- parietal lobe
Secondary area- sylvian fissure
“size of the cortical receiving area for impulses from a particular part of the body is proportional to the use of the part”
Thumb and lips-maximum representation
Vertical columnar arrangement