The phrase "speak softly and carry a big stick" implied that

A. protests and strikes were inefficient methods of bringing about reform

B. The US should adopt a policy of isolationism as well as militarism

C. force should be the primary tool of American diplomacy

D. military power should be available for retaliation if necessary

military power should be available for retaliation if necessary

Explanation:

The speak softly and carry a big stick is the approach use by the then American President, Theodore Roosevelt to approach its foreign policy with negotiation first, and if this fails, he resorted to the military attacks on the foreign soil.

He always find ways to resolve the foreign policy without the intervention of the American standby military that is ready to attack at any time.