TASK DEFINITION: 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.
PROBLEM: Category: "T.W." 
Clue: You might have learned to ride your bike with the help of these attachments

SOLUTION: training wheels

PROBLEM: Category: CROSSWORD CLUES "K" 
Clue: A "loopy" hobby that might needle you (8)

SOLUTION: knitting

PROBLEM: Category: THE MIDDLE AGES 
Clue: In 1955, 52-year-old Ray Kroc opened his first burger joint in the chain called not Kroc's but this

SOLUTION:
mcdonald\'s