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

The property 'calculation following' applies to instances of 'debt instrument yield', and 'option adjusted yield' is a subclass of 'debt instrument yield'. Which class can appear as the value of 'calculation following' for instances of 'option adjusted yield'?

A. loan prepayment formula
B. yield calculation method
C. loan pool prepayment model
D. weighted average time to receipt of cashflows

Answer: yield calculation method