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

The property 'farther than' applies to instances of 'distance', and 'debye length' is a subclass of 'distance'. Which class can appear as the value of 'farther than' for instances of 'debye length'?

A. sunspot number
B. d layer
C. distance
D. air traffic control center

Answer: distance