Industries That Are Truly Critical to National Defense Should Be

Industries that are truly critical to national defense should be protected from foreign competition if

A) the cost of procuring such defense items would otherwise rise.
B) adequate trade agreements with friendly countries cannot be implemented.
C) the military-industrial complex is to thrive.
D) the country's stock of vital human capital would suffer without these defense industries.
E) that is the only way to ensure their existence.