Why Was Chiang Kai-Shek Less Focused on Building Up the Chinese

Why was Chiang Kai-shek less focused on building up the Chinese military for fighting the Japanese after escaping to Sichuan?

A) He knew that war with Japan was going to be very drawn out.
B) He had already lost significant troops in Beijing.
C) He needed troops to rebuild the infrastructure after he had destroyed the dikes of the Yellow River.
D) He was preparing for a future battle with Mao's Communist army.
E) He planned to form an alliance with Russia and knew it would require a troop commitment.