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

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

A. manafacturing
B. supergranulation
C. unit
D. stewardship

Answer: unit