The Congress´s role on national security implies directly on the negotiations with another country, especially when they involve difficult situations, that is the option C. <em>(We should negotiate with treaty with country Z to fix this situation)</em>.
International relations are built through agreements between countries. This means that before any direct intervention in another country, one must try first - through diplomatic means - to agree to solve problems.
<u>Remembering that priority number 1 is to protect the citizen and society.</u>
For the other answers:
A. In practice this is done quite a bit today, which partly solves the question of national security, but can not be simplified that way.
B. This is more of a strategic economic issue than of national security.
D. This is also done today, which does not solve the question of national security because it involves a very high cost for the country and implies international inquiries about the influence exerted on the sovereignty of smaller countries.
