Final answer:
The most effective way for training partnerships on a track team is to pair runners of similar ability levels to ensure they are adequately challenged and can improve together.
Therefore, the correct answer is: option "Partners should be of similar ability levels."
Step-by-step explanation:
The BEST way for Kasima to pair training partners to most effectively help her runners succeed is by pairing partners of similar ability levels.
By doing so, each runner can be adequately challenged and supported by their partner, allowing for collective progression in terms of endurance, pace, and running technique.
On the other hand, pairing runners of very different ability levels might lead to frustration and demotivation, as the advanced runner may not be adequately challenged while the beginner may struggle to keep up.
Similarly, pairing based on weight and height or different backgrounds would not necessarily contribute to improvements in running performance, as these factors do not directly influence a person's running capacity and training needs.