think about the very subject of the question: meat. Meat needs to be refrigerated. MF DOOM looks at meat and says, "DON'T SPOIL IT!" how? you put it in a fridge.
The industrial revolution saw many advances and changes to the way we live (our lifestyles). We didn't always have air conditioning or cars and machinery. While knuckle couplers on trains DID make transporting goods like meat easier, this wasnt what revolutionized it because consumers wouldn't be able to eat meat in the first place. The single most important product here is the refrigerator car because it allowed meat to be kept well throughout long transportation times.
