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

The property 'has area' applies to instances of 'geometrical object 2d', and 'helical' is a subclass of 'geometrical object 2d'. Which class can appear as the value of 'has area' for instances of 'helical'?

A. Kinichilite
B. Goldichite
C. Smoky Quartz
D. area

Answer: area