D is the correct answer!!:)
May i have brainliest please?
Answer:
The field of national security safeguards against such threats. National security protects not only citizens but also the economic stability of national institutions. In the U.S., national defense has been a guiding principle of the government at least since 1947, when then-President Harry S. Truman signed into law the National Security Act. Among other things, this legislation created the secretary of defense cabinet position, under whose leadership all branches of the military operated.
“The colonists called it the French and Indian War, and it permanently shifted the global balance of power. By the mid-18th century, both the British and French wanted to extend their North American colonies into the land west of the Appalachian Mountains, known then as the Ohio Territory.”