What Was the Purpose of China's Northern Expedition

What was the purpose of China's Northern Expedition?

A) General Chiang's successful pursuit of warlords in several northern provinces.
B) The establishment of a Kuomintang government led by Chiang in Beijing.
C) A widespread purge of any suspected communists, during which tens of thousands of Chinese were killed.
D) The precursor to the Long March of 1934.
E) A march of protest by Chinese students who were upset about several elements of the Versailles Treaty.