Which task would the executive office of the president most likely be responsible for?
a: prosecuting corporations for violating federal laws
b: negotiating trade agreements with foreign countries
c: advising the president on national security issues
d: regulating the growth of the federal bureaucracy

I believe the answer is: C: Advising the president on national security issues

The executive office had the role to gather a group of agencies in order to support wide variety of works that shall be done by the president.

These varieties of works revolve around implementing the legislation that made by the Congress based on the allocation of budget. Example of their duties are: maintaining national security, create planning for government program, giving president advice regarding monetary policies, etc

the spanish  

hope this meaning spain btw