Answer:
D
Explanation:
The others arent even relevent to the question.
24= 3x+6
-6 -6
18 = 3x
— —
3 3
6 = x
The factor that helped the United States in making the inland transportation and commerce to be possible is in letter C. The intricate river system. I hope you are satisfied with my answer and feel free to ask for more if you have clarifications and questions.
Presumably journalism or science...