Avarious times the jews were ruled by all of the following except .
a. the persians
c. the greeks
b. the romans
d. the diaspora

At various times, the Jews were ruled by all of the following (the Persians, the Greeks, and the Romans) except for D. the diaspora.
The diaspora refers to any nation which moved from its original country. So here, the diaspora refers to Jews living outside Israel, and Jews cannot be ruled by Jews, which is why D is the correct answer.

The correct answer is b