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.
--------
Question: Category: LET'S TAKE A TRIP 
Clue: When this country broke away from Ethiopia in 1993, Haile Selassie Avenue in the capital became Harnet Avenue

Answer: eritrea


Question: Category: NAME THAT CENTURY 
Clue: President McKinley is assassinated

Answer: the 20th century


Question: Category: 1968 
Clue: He broke S. Africa's race barrier by transplanting black man's heart into white body

Answer:
christiaan barnard