In what year was the minimum national requirement to obtain a CDL signed into law?

Answer: B — 1986

The minimum national requirement to obtain a Commercial Driver's License (CDL) was established by the Commercial Motor Vehicle Safety Act, which was signed into law in 1986. This legislation aimed to improve road safety by setting minimum skills and knowledge required for commercial drivers across the United States. It mandated that states implement a standardized testing procedure to ensure that all CDL drivers meet specific competencies, thereby enhancing overall safety on the roads. This was a significant step in regulating commercial driving and ensuring more qualified individuals were behind the wheel of large vehicles.