Which exercise primarily focuses on triceps development?

The exercise that primarily focuses on triceps development is the triceps kickback. This movement specifically targets the triceps brachii, the muscle located at the back of the upper arm. When performing a triceps kickback, the elbow is stationary and positioned close to the body, allowing the triceps to fully contract and extend as the weight is lifted. This isolation of the triceps makes it an effective exercise for building strength and muscle mass in that area.

In contrast, the barbell bench press engages several upper body muscles, including the chest, shoulders, and triceps, but it does not isolate the triceps as effectively as the kickback. The dumbbell shoulder press is focused on shoulder muscle development, including the deltoids, and while it does engage the triceps as a secondary muscle, they are not the primary focus. The barbell squat is a lower body exercise primarily targeting the quadriceps, hamstrings, and glutes, with minimal involvement of the triceps. Therefore, the triceps kickback is the most focused exercise for triceps development among the choices provided.