The trade and commerce was the reason due to which San Francisco and Hong Kong were considered as part of same region.
Step-by-step explanation:
The countries such as San Francisco and Hong Kong were located on the same coast line. They both have equal power over the Pacific Ocean ad they are dependent on the ocean for the purpose of trade and commerce.
As the trade and commerce is considered as one of the most important aspect of the country, due to their usage of Pacific Ocean for it, San Francisco and Hong Kong are considered as part of the same region.