A plant absorbs 200 J/g of energy from the sun. A cow eats the plant and absorbs 120 J/g of energy. The cow is fed to a group of humans who absorb 70 J/g from the meat. What is the main reason the energy consumption decreases from one consumption to the next?
A) Some energy is wasted as heat.
B) The humans use some energy chewing.
C) The plant uses the energy to make sugar.
D) The cow uses some energy to make proteins.