Which of the following was an obstacle to calling the Council of Trent?

resistance by secular political leaders failure of the printing press to spread papal bulls protection of Protestants by German princes the excommunication of Martin Luther

The Council of Trent, which convened intermittently between 1545 and 1563, faced multiple obstacles, including:

1. **Resistance by secular political leaders**: Many secular rulers were concerned about losing power and control over their territories, particularly due to the ecclesiastical restructuring and potential centralization of power in the Catholic Church that were on the agenda of the Council.

2. **Protection of Protestants by German princes**: Some German princes had converted to Lutheranism and were protecting Lutherans within their territories. They opposed any council that might undermine the religious and political concessions they had obtained, especially through the Peace of Augsburg (1555), which allowed rulers to determine their territory's religion.

3. **The excommunication of Martin Luther**: Martin Luther's excommunication in 1521 certainly created religious and political rifts within Christendom, but it was less of an obstacle to calling the council than it was a catalyst for needing one. The split and growth of the Protestant Reformation emphasized the urgency of addressing the doctrinal disputes and abuses within the Church.

The failure of the printing press to spread papal bulls was not a significant obstacle. The advent of the printing press actually facilitated the spread of both Protestant and Catholic ideas, including the various edicts and communications from the Pope. This increased dissemination of information was, conversely, one of the methods by which the Council could relay its decisions, once it was convened.

The primary issue was the divisions within Christianity and the need for the Catholic Church to respond to the challenges of the Reformation, which included doctrinal disputes and the need for internal reform. The council was eventually called to reaffirm Catholic dogma, address abuses, and condemn Protestant heresies. Political maneuvering and negotiations were necessary to bring about the conditions for the council to take place, notably ensuring that it would serve the interests of the Catholic Church and the Holy Roman Emperor, among other Catholic sovereigns.