Task: Property Constraint Reasoning (ontology: Earth_Environment/SWEET)

The property 'has unit' applies to instances of 'quantity', and 'radiation medium interaction quantity' is a subclass of 'quantity'. Which class can appear as the value of 'has unit' for instances of 'radiation medium interaction quantity'?

A. gas flare
B. fuzzy set
C. granulation
D. unit

Answer: unit