Answer:
Correct answer is Al Smith.
Explanation:
Herbert Hoover is not the correct answer as Hoover was a Republican candidate who won the election and became a 31st President.
Harding is not correct answer as he was a 29th President of United States, who died in 1923.
Coolidge is not correct as he was President between 1923 and 1929 and did not ran for re-election in 1928.
Al Smith is correct answer as he was a candidate of elections and was under the attacks of the Klan since 1925 when he acknowledge that he will ran for the President.