Which of the following describes a product-oriented investigation?

A product-oriented investigation focuses on the outcomes or results of a movement rather than the processes or techniques involved in performing that movement. In the context of motor development, this means examining measurable results associated with a specific motor skill.

The correct choice reflects this concept by considering the velocity at which a ball can be projected by kicking. This measurement is a clear product of the kicking action, quantifying how effectively the skill is executed in terms of speed and distance the ball travels. Variables like speed and distance are concrete outcomes that can be assessed, making them ideal for a product-oriented approach.

In contrast, other options either focus on the mechanics of the movement or the psychological aspects affecting performance. The degree of extension around the hip joint when kicking addresses the biomechanics involved, while the role of vision pertains to the sensory aspects of performing a kick. Lastly, the effect of a child's self-worth on kicking examines psychological factors rather than the physical results of the kicking motion itself. Thus, these do not align with the product-oriented perspective, which is centered on the end results of motor performance.