Answer:
The correct answer is (b) States could not pass commerce laws in direct conflict with federal law.
In Gibbons v. Ogden, the Supreme Court ruled that the power to regulate interstate commerce was granted exclusively to the federal government by the Commerce Clause of the Constitution. This meant that state laws regulating commerce could not interfere with or be in conflict with federal laws. Therefore, state commerce laws were subject to the authority of federal law, and could not override federal commerce laws.