What is the length of the chain used for the line-to-gain equipment?

The length of the chain used for the line-to-gain equipment in NFHS football is specifically designed to accurately measure the distance between the tackle box and the line of scrimmage. The correct answer states that the chain measures 10 yards to the inner edge of the forward rod. This standard measurement allows officials and players to easily determine whether a team has achieved a first down.

The 10-yard measurement reflects the typical distance required for a first down, which is a fundamental rule in the game of football. The inner edge of the forward rod marks the spot where the new line of scrimmage will be if a team successfully gains that distance. This setup is crucial for maintaining the flow of the game and ensuring that teams can gauge their progress on the field accurately.

The other options do not align with the established rules and practices regarding line-to-gain equipment. They would either denote incorrect distances or setups that would not effectively communicate the necessary information during play. The specifications outlined in option B are consistent with standard football regulations, making it the correct choice.