Which one of these is a proper use by the President of their for foreign policy power to recognize a foreign nation?

putting a U.S embassy in a foreign country

sending diplomats to a foreign country

negotiating a treaty with a foreign country

appointing a foreign country's secretary of state

The proper use by the President of their foreign policy power to recognize a foreign nation is negotiating a treaty with a foreign country. This can establish formal diplomatic relations between the two countries and provide a framework for cooperation on various issues.