The correct option is D) a Separatist.
The group that would have most likely spoken the statement above is a separatist.
In the 16th and 17th century, the terms Separatist meant that people wanted to separate from the church of England to form other churches that were independent. The English Protestants of that time grew tired of the corruption they saw in the church of England. That is why on the passage we read that "the only way we can practice pure religion, based on the Bible's Sermons, is to break away from the church..."
The other options of the question were a) Catholic, b) Protestant, and c) Puritan.