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.
--------
Question: Category: 2-LETTER WORDS 
Clue: It's used to attract attention to something sighted on a ship, like land or a sail

Answer: ho


Question: Category: MARK ANTONYMS 
Clue: The traditional mark of someone who can't sign his name has this opposite in tic-tac-toe

Answer: o


Question: Category: TELL ME "Y" 
Clue: The capital of Jiangsu province is located on a bend in this river

Answer:
the yangtze