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: LAND "HA"! 
Clue: Ho Chi Minh's remains are on display in a mausoleum in Ba Dinh Square in this Vietnamese city

SOLUTION: hanoi

PROBLEM: Category: WITCHCRAFT 
Clue: Until Dorothy showed up, these small folks toiled as slaves for Oz' Wicked Witch of the East

SOLUTION: munchkins

PROBLEM: Category: "OVER" & "UNDER" 
Clue: In "The Caisson Song", it precedes "We have hit the dusty trail"

SOLUTION:
"over hill, over dale"