Which English monarch did some Protestants perceive as a threat to reverse the action taken in this document?

The correct answer is Mary I. Some Protestants perceived her as a significant threat due to her staunch Catholic beliefs and her efforts to restore Roman Catholicism in England after the Protestant reforms initiated by her father, Henry VIII, and furthered under her half-brother, Edward VI. Mary I's marriage to Philip II of Spain and her persecution of Protestant reformers during her reign reinforced the fears of many Protestants that she would undo the religious changes implemented previously. Her reign marked a concerted effort to revert England back to Catholic practices, which prompted resistance and concern among Protestant communities who had embraced the Reformation.

Henry VIII, while pivotal in the establishment of Protestantism in England, ultimately initiated the split from the Catholic Church for personal and political reasons rather than strict theological motivations. Edward VI, known for his Protestant leanings, further advanced Protestant reforms but died young, leaving Mary to restore Catholicism. Elizabeth I, being the daughter of Henry VIII, navigated a middle path between Protestantism and Catholicism, thus reducing the immediate threat perceived by Protestants compared to Mary.