With regard to the Great Depression, the Republican Party
a. was blamed, rightly or wrongly, by most Americans for the Depression.
b. expected to maintain control despite the Depression.
c. quickly nominated FDR to fight the Depression.
d. all the above.
The best answer of the ones that you have given us here is A.
The Great Depression was, fairly or not, blamed on the Republican Party. It had been in power (controlling the presidency) for the entire decade of the 1920s. This made it the target of the anger of many people. This can be seen, for example, in the fact that the shantytowns where many of the poor were forced to live ended up being called "Hoovervilles." This shows that the people were blaming President Hoover for their plight.
The Republicans hoped, but did not expect, to win the presidency in 1932. They lost to Franklin Roosevelt, who was a Democrat.