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

Which of the following classes is one valid superclass of 'methanopterin-containing compound metabolic process'?

A. phosphate-containing compound metabolic process
B. (R)-2-hydroxyglutarate dehydrogenase activity
C. (1,4)-alpha-D-glucan 1-alpha-D-glucosylmutase activity
D. 'de novo' cotranslational protein folding

Answer: phosphate-containing compound metabolic process