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
[{'content': 'Secondary tumour may spread to the orbit by all the following except \nSelect and explain. \nA. Direct spread from lids, B. Blood, C. Lymphatic channels, D. Direct spread from cranial cavity', 'role': 'user'}, {'content': 'Answer: C \nExplanation: No spread to the orbit by lymphatic channels.', 'role': 'assistant'}]