The correct answer is Hoover's policies had failed to provide sufficient economic relief.
Hoover was president when the US economy took a turn for the worse. Events like the Stock Market Crash of 1929 and the widespread bank closures across the country due to lack of currency were events that negatively affected millions of Americans. When these hard economic times hit, the American people looked to the government in order to fix the problem.
However, Hoover was not an advocate for government interference in the economy. Hoover felt that the economy worked best when the government interefered as little as possible (also known as a "laissez faire" approach). This idea was wildly unpopular with citizens, as millions of people became homeless or jobless over the course of a couple short years.
Hoover's lack of direct financial assistance to citizens resulted in an easy win for President Franklin D. Roosevelt.
