What component transfers force from the primary shoe to the secondary shoe?

The correct answer is the adjusting screw. In drum brake systems, the adjusting screw plays a crucial role in transferring force from the primary shoe to the secondary shoe. When the brake pedal is applied, the wheel cylinder pushes the primary shoe outward against the drum. The adjusting screw, which connects the primary and secondary shoes, helps to keep the shoes properly spaced and allows force to be transmitted effectively from the primary shoe to the secondary shoe during braking.

This design ensures that both shoes engage the brake drum adequately, helping to increase the overall braking force and efficiency. The adjusting screw also assists in maintaining the optimal distance between the shoes and the drum as they wear down, which contributes to consistent braking performance.