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

After reasoning, which of the following classes is one valid superclass of 'plasmacytoid dendritic cell cytokine production'?

A. outer fibrous layer of perichondrium
B. negative regulation of mesoderm formation
C. macromolecule biosynthetic process
D. positive regulation of iron ion import across plasma membrane

Answer: macromolecule biosynthetic process