Why Were the Nationalist Leaders of China, Vietnam, and India

Why were the nationalist leaders of China, Vietnam, and India impressed with the quick Japanese victories over European and American colonial outposts in Southeast Asia?

A) They were startled by how easily Japan had humbled the colonial rulers.
B) They themselves had tried to bring down European colonial powers with military might for decades.
C) They began to see the merit of Japan's proposed Greater East Asia Co-Prosperity sphere.
D) They began to consider a pan-Asian nation under Japanese leadership.