This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: Head and neck, Subject name: Anatomy
Cribriform plate is a pa of? 
Select and explain. 
A. Ethmoid, B. Maxilla, C. Nasal, D. Frontal
A: Ethmoid
Answer: A: Ethmoid 
Explanation: Ethmoid is a very light cuboidal bone situated in the anterior of base of cranial cavity between the two orbits; 1. Pa of medial orbital walls 2. Pa of nasal septum 3. Pa of root of orbit 4. Lateral walls of the nasal cavity Ethmoid bone comprises 1 cribriform plate 2. Perpendicular plate 3. A pair of labyrinth Ref BDC volume volume3; 6 th edition pg 45