Task: Inferred Class Relation Reasoning (ontology: Sciences/Biology)

After reasoning, which of the following classes is one valid superclass of 'germinal center'?

A. kidney outer medulla collecting duct epithelial cell
B. anatomical structure
C. regulation of myeloid dendritic cell antigen processing and presentation
D. ophthalmotemporal branch of external ophthalmic artery

Answer: anatomical structure