Given a text T, and several options, according to the question posed in the text T to choose the most appropriate option from the options as the answer, please directly output the most appropriate option, do not need to output the explanation.

Which of the following statements about commodity investing is invalid?
Option A:Few commodity investors trade actual physical commodities.
Option B:Commodity producers and consumers both hedge and speculate.
Option C:Commodity indexes are based on the price of physical commodities.

Answer: C