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: ENT
CSF Rhinorrhea occurs d/t 
Select and explain. 
A. Roof of orbit, B. Frontal sinus, C. Cribriform plate of ethmoid bone, D. Sphenoid bone
C: Cribriform plate of ethmoid bone
Answer: C: Cribriform plate of ethmoid bone 
Explanation: Commonest area of # causing CSF Rhinorrhea → cribriform plate of ethmoid bone as it is extremely thin.
Other possible areas of # causing CSF Rhinorrhea Frontal sinus (Posterior wall) or of the anterior cranial fossa.
Difference between CSF Rhinorrhea & allergic or vasomotor rhinitis CSF contains glucose which can be demonstrated by chemical tests.
CSF when collected into a test tube and allowed to stand, it remains clear in contradistinction to nasal discharge that leaves a sediment because of mucus and other proteins.
Nasal discharge stiffens the handkerchief and CSF dries soft in it.
Treatment: Prophylactic antibiotics & X-ray * If more than 2 wks then correct it surgically.