How was the struggle between protestantism and the catholic church a war of ideas?

Whereas traditional Catholic teaching held that salvation is achieved by both faith and good works, protestants held that salvation comes by faith alone (sola scriptura, sola fide, sola gratia) , irrespective of good works or the the sacraments. Protestants believed that authority exists in the Bible alone, whereas Catholic theology claimed that authority rests both in the Bible and in the traditional teachings of the church. Additionally, while the medieval church stressed the superiority of the monastic and religious life over the secular, Protestants disagreed and argued that every person should serve God in his or her individual calling. The protestants generally only believed in the sacraments that were mentioned in the bible (Baptism and the Eucharist), whereas the Catholics believed in the 7 sacraments.

Correct answer for apex is d.