Task: Class Definition Understanding (ontology: Business_Finance/Financial_Industry_Business_Ontology)

Which of the following definitions best describes 'commodity index'?

A. reference index that is a function of credit events that change the value of an underlying portfolio
B. generated resource that is a viscous liquid derived from petroleum, including for use as fuel, or as a lubricant, and the manufacture of many types of paints, plastics, and other materials
C. benchmark whose constituents are exclusively equity instruments
D. investment vehicle that tracks a basket of commodities to measure their price and investment return performance

Answer: investment vehicle that tracks a basket of commodities to measure their price and investment return performance