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: Surgery
What is sternocleidomastoid tumor? 
Select and explain. 
A. Hematoma of sternocleidomastoid muscle, B. Malignancy of sternocleidomastoid muscle, C. Lymphnodes related to the muscle, D. Benign tumor of the said muscle
A: Hematoma of sternocleidomastoid muscle
Answer: A: Hematoma of sternocleidomastoid muscle 
Explanation: None