Answer:
Step-by-step explanation:
The murder of 6 million Jews living in the countries conquered by Germany during WWII.
Russia was never conquered -- not during WWII. Mind you there were some very grisly battles, and St. Petersburg was occupied for nearly 900 days.
The Jewish People in Europe could only wish for A to happen. By the time they realized what was happening, no country that was safe was willing to take them. Not A as an answer
While B is true, it was a side effect of D. Dead people cannot run businesses.