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: PRESIDENTS 
Clue: Under an act passed in 1958, they became the first two former presidents eligible for a pension
[A]: harry s. truman & herbert hoover


[Q]: Category: INVENTIONS 
Clue: The delivery system for Ban deodorant, introduced in 1955, was based on this invention, patented in 1938
[A]: ball point pen


[Q]: Category: U.S. CURRENCY 
Clue: It's the only building to appear on 2 current U.S. bills; one is an interior view, the other an exterior view
[A]:
independence hall