The Main Problem with Accepting the National Security Argument as a Valid

The main problem with accepting the national security argument as a valid reason to restrict international trade is that

A) other countries could have produced the goods more efficiently
B) almost all industries could be described as being vital to national security
C) technology secrets are difficult to keep from other countries in this age of computer information
D) it will become too expensive to produce national security goods within the country
E) in reality, tariffs are impossible to enforce effectively because of the black market