Why Did Japan Invade Manchuria in the 1930s

Why did Japan invade Manchuria in the 1930s?

A) To seize control of the railroad there into Russia
B) To take the iron and coal deposits
C) To use as a staging ground to invade Russia
D) To have a warm water port on the mainland
E) To prevent the Chinese from using the port there as an launch point to invade Japan