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
The most common malignant orbital tumor in children is: 
Select and explain. 
A. Rhabdomyosarcoma, B. Cavernous Hemangioma, C. ALL, D. AML
A: Rhabdomyosarcoma
Answer: A: Rhabdomyosarcoma 
Explanation: The most common malignant orbital tumour in children is Rhabdomyosarcoma. Rhabdomyosarcoma is the most common primary malignant orbital tumor in the pediatric age group. Ref: Head & neck surgery - otolaryngology: Volume 2 - Page 1501; Recent Advances in Ophthalmology - Volume 9 - Page 48.