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: ANIMALS 
Clue: Also called a warrigal, this wild dog is one of the few nonmarsupial mammals of Australia
dingo

Category: NEXT LETTER AFTER... 
Clue: ...J in the Macedonian alphabet
k

Category: SINGERS 
Clue: In 1984 she had her first Top 10 hit in the U.S. with "Borderline"

madonna