C. Many countries have treated Jewish people poorly and forced them to leave.
Throughout history, Jewish people have faced persecution and discrimination in many countries, often being forced to leave their homes and seek refuge elsewhere. This has contributed to the spread of Judaism around the world, as Jewish communities have formed in new places as a result of these forced migrations. This factor has most contributed to the spread of Judaism around the world, as opposed to factors such as powerful kingdoms forming alliances with Jewish leaders, Jewish missionaries traveling around the world seeking converts, or Jewish empires establishing colonies around the world.