Which of the Following Best Describes Why the United States

Which of the following best describes why the United States has been reshaping its military planning in recent years?

A) because the war on terror will require increased engagement in more countries of the type seen during the occupation of Iraq
B) because the war on terror requires the United States to be prepared for a nuclear holocaust
C) because the United States has to deal with terrorists,who are all suicide bombers who care nothing for life
D) because the war on terror requires the military to confront unconventional tactics such as ambushes and hostage taking