What are the food administration the war industries board and the railroad administration example of?

They're all examples of Government Agencies created to help support the country during war.

Food Administration was a government agency responsible for controlling food reserves for U.S. and Allies' troops.

The War Industry Board, as mentioned before, "was created to coordinate the purchase of war supplies."

The U.S. Railroad Administration was a national railroad system in the US, which was created to improve railroads in the US. During war, the U.S. became a large provider of munitions, and the railroad system at the time couldn't handle the demand the war created. Thus, the investment in the national railroad system was made.