Commodities That Are Traded in Futures Markets Are Usually Grouped

Commodities that are traded in futures markets are usually grouped into what three categories?

A) Agriculture products, metals, and energy.
B) Grains and oil seeds, livestock, and energy.
C) Food and fiber, crude oil and natural gas, and metals.
D) Crude oil and gas, agricultural products, and livestock.
E) None of the categories above.