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 simplicity, answers should be in all lower cased letters.

[Q]: Category: A BUSINESS IS BORN 
Clue: The first drug-store in this chain began operating out of a Chicago hotel in 1901; in 2009 the 7,000th store opened
[A]: walgreens


[Q]: Category: FORWARDS & BACK WORDS 
Clue: Shrek & "therefore" (follows "cogito")
[A]: ogre & ergo


[Q]: Category: ANATOMY 
Clue: The term for the brain & spinal cord, often abbreviated CNS
[A]:
central nervous system