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: Medicine
In idiopathic polymyositis, following are seen except-a) Ocular muscles commonly involvedb) Pharyngeal muscles involvedc) Cutaneous manifestationsd) Proximal limb muscles invariably involved 
Select and explain. 
A. a, B. bc, C. ac, D. b
C: ac
Answer: C: ac 
Explanation: None