单选题
In the early 20th century, the socialist ideology spit into two broad camps. The ( ) believed that socialism could be achieved only through violent revolution and totalitarian dictatorship, while the ( ) committed themselves to achieving socialism by democratic means and turned their backs on violent revolution and dictatorships.
A、individualists, collectivists
B、social democrats, communists
C、collectivists, individualists
D、communists, social democrats