You will be given a trivia clue, and the category it belongs to. You should answer with the best answer that belongs in the category and is described by the clue. For consistency, answers should be in all lower cased letters.

[Q]: Category: "T.W." 
Clue: You might have learned to ride your bike with the help of these attachments
[A]: training wheels


[Q]: Category: ARE YOU READY FOR SOME FOOSBALL 
Clue: It's illegal to rotate the rods more than this many degrees, so forget about spinning off a "slap" shot
[A]: 360


[Q]: Category: TRANSPORTATION 
Clue: In the 19th century Gustavus Swift developed this type of railway car to preserve his packed meat
[A]:
refrigerator car