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

The property 'was controlled by' applies to instances of 'process', and 'obervation' is a subclass of 'process'. Which class can appear as the value of 'was controlled by' for instances of 'obervation'?

A. artifact
B. retroarc foreland basin
C. validation evidence
D. radiative forcing

Answer: artifact