What is a call to arms as infidels? Im in school right now and I don't understand.?

Help please! I have to use it for a powerpoint and this is the last day I have to work on it. What is it and what is it known as? The exact question is Call to arms against infidels is known as - A. Islam B. Jihad C. Terrorism or D. Draft? How do I answer it if I don't know what it is? Please help we only have thirty minutes of class left!!