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

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

A. microburst
B. agent
C. line integral
D. marine bird

Answer: agent