Which of the Following Is an Example of Deterrence

Which of the following is an example of deterrence?

A) The United States enters into negotiations with one country by signing a treaty with another nation-state.
B) The United States moves to attack the Soviet Union,believing that the Soviet Union is contemplating hostile action.
C) The United States moves to increase the size of the military to discourage attack.
D) The United States avoids permanent alliances with foreign powers by remaining neutral.
E) The United States moves to promote security by establishing trade relations with another country.