Answer:
The answer is definitely D.
Step-by-step explanation:
Let me go through each one. It would not be A because that answer relates to the Opium War which was during the 1800s not the 1900s.
It would not be B because the Cultural Revolution had nothing to do with Hong Kong or United Kingdom.
It would not be C because the Japanese was not involved with any of the Cultural Revolution activities, therefore leaving us with Answer D.
Hope this helps.