How can a president use foreign policy power to recognize a foreign nation?

Question

a. sending diplomats to a foreign country
b. appointing a foreign country’s secretary of state c. negotiating a treaty with a foreign country
d. putting a U.S. embassy in a foreign country

Answer 1

a. sending diplomats to a foreign country
d. putting a U.S. embassy in a foreign country

Answer 2

it can only be one

Answer 3

If it has to be only one option, then the correct answer would be:
a. sending diplomats to a foreign country