This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: C.N.S, Subject name: Medicine
Isolated 3rd nerve palsy is Seen in- 
Select and explain. 
A. Frontal lobe tumour, B. Webers syndrome, C. Diabetes, D. Lateral medullary syndrome
C: Diabetes
Answer: C: Diabetes 
Explanation: *Diabetes ,hypeension and vascular disease are major risk factors *Isolated nuclear oculomotor palsy is rare. Third nerve palsy typically manifests as diplopia and ptosis.The diabetic 3rd nerve palsy may affect isolated superior or inferior division of the oculomotor nerve, but diplopia usually exists Ref Harrison20th edition pg 2456