Final answer:
The subject of this question is Social Studies and the grade level is High School.
Step-by-step explanation:
The subject of this question is Social Studies and the grade level is High School. The regulation mentioned in the question is related to the construction of U.S. highways and the use of foreign steel. The question asks for the appropriate subject and grade level, and based on the provided information, Social Studies is the most relevant subject and the question is appropriate for High School level.