Which of these examples best represents an area of United States foreign policy? A.
Congress votes to increase the salaries of American armed forces members serving overseas.
B.
The Senate Judiciary Committee holds a hearing about proposed changes in immigration policy.
C.
The Central Intelligence Agency announces that one of its international spies has been captured.
D.
The president appoints an ambassador to protect American interests in a particular country.

D.  The president appoints an ambassador to protect American interests in a particular country.

Explanation:

The foreign policy of the United States is its interactions with foreign nations and how it sets standards of interaction for its organizations, corporations and system citizens of the United States. The officially stated goals of the foreign policy of the United States of America, including all the Bureaus and Offices in the United States Department of State, as mentioned in the Foreign Policy Agenda of the Department of State, are "to build and sustain a more democratic, secure, and prosperous world for the benefit of the American people and the international community".