The answer is definitely:
A. Migrated into England from Germanic regions of Europe (from 5th century onwards..)
I got this from Brittinica.com and these are the most important details from it:
'Open Door policy, statement of principles initiated by the United States in 1899 and 1900 for the protection of equal privileges among countries trading with China and in support of Chinese territorial and administrative integrity.The principle that all countries should have equal access to any of the ports open to trade in China. But after Japan’s defeat in World War II (1945) and the communist victory in China’s civil war (1949), which ended all special privileges to foreigners, made the Open Door policy meaningless.
I hope this was helpful.
