This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: Orbit, Subject name: Ophthalmology
Blow out fracture affects which orbital wall ? 
Select and explain. 
A. Lateral wall, B. Posteromedial part of orbital floor, C. Superior wall, D. Anterosuperior roof
B: Posteromedial part of orbital floor
Answer: B: Posteromedial part of orbital floor 
Explanation: Ans. is 'b' i.e., Posteromedial part of orbital floor * 'The orbital floor overlies the maxillary sinus without reinforcement, therefore is weaker and more blowouts tend to occur here especially in the posteromedial floor'