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

The property 'is primary contract for' applies to instances of 'written contract', and 'transferable contract' is a subclass of 'written contract'. Which class can appear as the value of 'is primary contract for' for instances of 'transferable contract'?

A. contract third party
B. contract party
C. written contract
D. birth certificate

Answer: written contract