This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: Nervous System, Subject name: Surgery
A 64-year-old man presents with headache and left-sided upper extremity weakness. The MRI findings suggest that this is a glioblastoma multiforme. This is because the tumor exhibits which of the following? 
Select and explain. 
A. It is regular in shape., B. It is well demarcated from surrounding brain tissue., C. It shows a ring pattern of enhancement with intravenous contrast and has a non-enhancing necrotic center., D. It shows an absence of surrounding white-matter edema.
C: It shows a ring pattern of enhancement with intravenous contrast and has a non-enhancing necrotic center.
Answer: C: It shows a ring pattern of enhancement with intravenous contrast and has a non-enhancing necrotic center. 
Explanation: Glioblastoma multiforme grows rapidly, and the tumor often contains a necrotic core that occurs as its growth surpasses its blood supply. Additional features on MRI include irregular shape, poor demarcation from surrounding brain tissue, and the presence of variable amount of surrounding white-matter edema