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

The property 'has quotation settlement basis' applies to instances of 'quoted exchange rate', and 'currency forward rate' is a subclass of 'quoted exchange rate'. Which class can appear as the value of 'has quotation settlement basis' for instances of 'currency forward rate'?

A. currency spot mid rate
B. exchange rate structure
C. duration
D. exchange rate volatility

Answer: duration