A plant uses carbon dioxide and water to form food and oxygen. Why is this a chemical change? A. The mass of the plant increases greatly.

B. The properties of water and food are same.

C. The plant increases in height as food is produced.

D. The properties of carbon dioxide and oxygen are different.

Automobile fuel efficiency is often measured in miles that the car can be driven per gallon of fuel (mpg). heavier cars tend to have lower fuel efficiencies (lower mpg ratings). which variable (weight or fuel efficiency) is most naturally considered the explanatory (predictor) variable in this context?