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: Pathology
Osteomyelitis begins as an inflammation of 
Select and explain. 
A. Cortical bone, B. Periosteum, C. Medullary bone, D. Periosteum and inner cortex
C: Medullary bone
Answer: C: Medullary bone 
Explanation: None