What was the difference between wartime conservation and wartime rationing

Wartime Conservation
During WWII workers would carpool to work or ride bicycles to save gasoline and rubber. People participated in nationwide drives to collect scrap iron, tin cans, newspaper, rags, and even cooking grease to recycle and use in war production.

Wartime Rationing 
Taking items that are in short supply and distributing them according to a system. For instance, during World War II, gas, sugar, and butter were a few of the items rationed in the United States.

Explanation: All of them seem correct