What Were the Significant Differences Between Contenders for Control of the Communist

What were the significant differences between contenders for control of the Communist Party after Lenin's death in 1924?

A) Stalin wanted to focus on communism's establishment in Russia, and he believed socialism could survive "in one country."
B) Trotsky argued for the continuation of the NEP.
C) Stalin wanted an alliance with Germany and Italy because fascism seemed the best way to industrialize Russia rapidly.
D) Trotsky advocated maintaining an alliance with China, convinced that an Eastern Bloc of Communism could overthrow the industrialized West.
E) There was no significant difference in policies; it was a personal rivalry between Stalin and Trotsky.