The correct analysis of the timeline indicating how antisemitism grew in Europe during the 1500s is:
a. Both Catholic and Protestant leaders made life difficult for European Jews.
This choice is supported by the events listed on the timeline. The expulsion of Jews from Spain in 1492 was a significant act by the Catholic rulers, highlighting the institutionalized antisemitism present in Catholic nations. The establishment of the first Jewish ghetto in Venice in 1516 further reflects the growing segregation and marginalization of Jews in Catholic regions. Additionally, Martin Luther’s condemnation of Jews in 1543, despite his earlier protective stance, shows that Protestant leaders also contributed to antisemitic sentiments. Finally, Pope Paul IV's establishment of the Roman ghetto and his order for the burning of Jews in 1555-1556 demonstrates an extreme form of antisemitism endorsed by the Catholic Church.
Collectively, these events indicate that antisemitism was not limited to one denomination or geographic area; rather, it was pervasive among both Catholic and Protestant leaders throughout Europe during the 1500s.