Task: Class Relation Understanding (ontology: Sciences/Biology)

Which of the following classes is one valid superclass of 'CX3C chemokine receptor 1 (mouse)'?

A. CX3C chemokine receptor 1
B. 6-aminopurines
C. 2nd arch mesenchyme from neural crest
D. 2nd arch mesenchyme

Answer: CX3C chemokine receptor 1