In my opinion,self-preservation refers to the preservation of Japan’s territories as well as the achievement of self-sufficieny(autarky). Thus, I feel that Sources B,C and D support the statement while Sources A and E do not.
Source B supports the hypothesis. It states the two reasons why Japan went to war and is reliable because it is a report of the Japanese government conference held in 1941. Source B states that Japan will “seek to establish a solid basis for security and preservation of the nation”and “advance south”. This shows that Japan wanted to protect its territories like China and sought to establish its military so that it could conquer