Answer:
C.) The Persecution of Jews in Russia and Eastern Europe
Explanation:
I am going through the process of elimination.
A.) A response to the Balfour Declaration.
Cannot be right, because the Balfour Declaration was issued by the British government in 1917.
B.) The Holocaust.
This took place from 1941 to 1945.
D.) Fascist Regimes in Germany and Italy.
Those fascist regimes began to rise after WWI, which is also in the 1900s.
So,
C.) The persecution of Jews in Russia and Eastern Europe.
Is your best bet, because I know there was some Pogroms happening then, The first Aliya happened in 1882, where over 20,000 Russian Jews were fleeing prosecutions, otherwise referred to as Pogroms.
The term aliya refers to the act of immigration to the Holy Land by Jews. It is also used to refer to the different waves of Jewish immigration to Israel (or Palestine given the time period)
I hope this answer makes sense to you. Good Luck