Which assessment would best evaluate a client's agility performance?

Evaluating a client's agility performance is best accomplished through an assessment that specifically measures their quickness and ability to change direction effectively. The T-test is designed to assess agility by requiring the individual to sprint, touch points in a specific configuration, and change direction rapidly. This process assesses not just speed, but also coordination, balance, and the capacity to make quick adjustments, all of which are fundamental aspects of agility.

The other assessments mentioned, while useful for measuring different physical attributes, do not specifically target agility. A bench press test focuses on upper body strength, the single-leg squat assesses lower body strength and balance, and the vertical jump measures power and explosiveness, primarily involving vertical movements. None of these options accurately captures the dynamic, multi-directional movement patterns that agility entails, making the T-test the most appropriate choice for evaluating agility performance.