Answer:
The factor for which Japan invaded Manchuria is simply because they want to extract and exploit their natural resources.
Step-by-step explanation:
Japan, despite being an industrialized nation, lacks some fundamental natural resources. However, having found out that the region has natural resources in abundances such as oil, rubber, and lumber. Then by 1931, Japan invaded the region without declaring war.
Hence, the correct answer to this question is "The factor for which Japan invaded Manchuria is simply because they want to extract and exploit their natural resources."