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: Ophthalmology
Most common extraocular muscle involved in Grave's disease 
Select and explain. 
A. Superior rectus, B. Inferior rectus, C. Medial rectus, D. Superior oblique
B: Inferior rectus
Answer: B: Inferior rectus 
Explanation: IR > MR > SR > LR > obliques.