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

The property 'has 2D boundary' applies to instances of 'material entity', and 'system' is a subclass of 'material entity'. Which class can appear as the value of 'has 2D boundary' for instances of 'system'?

A. response to stimulus
B. anatomical axis
C. gas molecular entity
D. immaterial entity

Answer: immaterial entity