Crusades against Muslims were called for what?

Crusades against Muslims were created to stop Islamic invasion of Europe in the middle ages.

The Crusades were a series of religious wars between Christians and Muslims started primarily to secure control of holy sites considered sacred by both groups. Throughout the remainder of the 13th century, a variety of Crusades aimed not so much to topple Muslim forces in the Holy Land but to combat any and all of those seen as enemies of the Christian faith.

Explanation:

answer; /// i believe that the correct answer is (a) making presentations;

in what process is there a multiple choice answer?