Why Did Otto Von Bismarck Grant Germans Universal Male Suffrage

Why did Otto von Bismarck grant Germans universal male suffrage despite his conservative principles?

A) He believed the Bundesrat, the upper house made up largely of German princes, could effectively block any of the more populist measures the Reichstag might propose.
B) He thought that only by appealing to a wide segment of the German people could he hope to secure enough support for a radical reform of Germany's fledgling social welfare system.
C) He understood that the future lay with democratic government and especially with the working classes, who he believed would always vote in favor of war.
D) He trusted that "ordinary" Germans would be more conservative and loyal to the monarchy than the liberals in the Prussian parliament.