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.

Category: WEIGHTS & MEASURES 
Clue: To the Ancient Greeks, 4 of these made a palm
fingers

Category: MOTHER GOOSE 
Clue: It's the type of nail referred to in the nursery rhyme "All for Want of a Nail"
a horseshoe nail

Category: HISTORIC QUOTES 
Clue: He told the 1984 Dem. Convention, "Our flag is red, white, & blue, but our nation is a rainbow"

jesse jackson