Task: Property Constraint Reasoning (ontology: Business_Finance/Financial_Industry_Business_Ontology)

The property 'is supplied by' applies to instances of 'product', and 'contractual product' is a subclass of 'product'. Which class can appear as the value of 'is supplied by' for instances of 'contractual product'?

A. transaction event
B. negotiable commodity
C. supplier
D. customer identifier

Answer: supplier