Submarines as a realistic Chinese naval priority

What should the Republic of China have built for its navy in the 1930s, and where might it obtain submarines?

It should have prioritized submarines, probably bought from Britain, though American, French, or Dutch options were conceivable.

The Republic of China had little coherent naval reconstruction before its war with Japan. Submarines would offer a more realistic priority than trying to match Japan with surface capital ships. Britain is the likeliest supplier, with the United States or France also possible. Germany's treaty restrictions ruled out direct construction, though a Dutch-built design with German influence might provide another route. Undersea warfare offered an asymmetric procurement choice for a state with limited naval resources.