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
Most common route for metastasis of oral cancer is by: 
Select and explain. 
A. Direct extension, B. Lymphatics, C. Blood vessels, D. Aspiration of tumor cells
B: Lymphatics
Answer: B: Lymphatics 
Explanation: None