Which of the Following Is a Reason Why a Book

Which of the following is a reason why a book on interstate conflict should address the question of civil war?

A) Civil unrest within small countries is the responsibility of the United Nations,and therefore it is important to international relations.
B) Civil wars put great strain on domestic legal systems through social media.
C) There may be spillover effects from one state's civil war that affect other countries' stability and security.
D) Terrorism tends to be contained only within their host countries.