Final answer:
The subject of this question is Social Studies, and the question pertains to federal requirements for maximum gross vehicle weight. The correct answer is option A, the bridge formula. The bridge formula is a federal requirement that calculates the maximum weight a vehicle can carry based on axle spacing.
Step-by-step explanation:
The subject of this question is Social Studies. The question pertains to federal requirements regarding the maximum gross vehicle weight. The correct answer is A, the bridge formula. The bridge formula is a federal requirement that calculates the maximum weight a vehicle can carry based on axle spacing, which helps ensure that bridges are not damaged by overweight vehicles.