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.

Q: Category: UNITS OF MEASURE 
Clue: The scale on the bottom of a sextant is in these units

A: degrees
****
Q: Category: LETHAL WEAPONS 
Clue: In the largest man-made explosion in history, the USSR detonated a 50-megaton one of these in 1961

A: a hydrogen bomb
****
Q: Category: BOOKS OF THE BIBLE 
Clue: The flood & the birth of Isaac are covered in this book

A:
genesis
****