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.

Category: 1998 BESTSELLERS 
Clue: 35 years after her death, she's the subject of a new collection of poems by her husband
sylvia plath

Category: SCIENTISTS 
Clue: In 1543 he wrote, "Finally we shall place the sun himself at the center of the universe"
nicolaus copernicus

Category: ENGLISH HISTORY 
Clue: 11th century England had 2 kings with this name, one a Dane & one a Saxon

harold