Task: Property Constraint Reasoning (ontology: Sciences/Biology)

The property 'relation between physical entity and a process or stage' applies to instances of 'independent continuant', and 'purine' is a subclass of 'independent continuant'. Which class can appear as the value of 'relation between physical entity and a process or stage' for instances of 'purine'?

A. xenobiotic catabolic process
B. obsolete MiR2
C. obsolete predominantly gray regional part of inferior colliculus
D. occurrent

Answer: occurrent