I believe the answer is: C. diplomats and ambassadors
Diplomats and ambassadors are deployed to live in foreign country as their country's representation in that foreign land. They played a huge role in negotiating political and trading agreements with foreign countries and also had the role in protecting the rights of citizens that live in foreign countries.
You’re right, it’s anti fed. The Anti-Federalists were afraid of the Law being too strong and abusing them. They needed a compromise, which was the Bill of Rights.