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

The property 'adjacent to' applies to instances of 'independent continuant', and 'purine' is a subclass of 'independent continuant'. Which class can appear as the value of 'adjacent to' for instances of 'purine'?

A. independent continuant
B. obsolete connective tissue proper
C. CLM 1000053
D. obsolete regional part of neuraxis cavity

Answer: independent continuant