Which of the following is true about flexibility?

Flexibility is fundamentally understood as the ability of muscles and joints to stretch and move through their full range of motion. This capability allows for better performance in physical activities and can reduce the risk of injuries to some extent. It involves not only the extensibility of muscles but also the capacity of tendons and connective tissues to lengthen. This attribute is crucial for athletes and anyone engaged in regular physical activity, as it enhances overall mobility and functionality.

While the other statements may also touch upon aspects related to physical fitness, they do not define flexibility accurately. For example, the notion of joint stability is different from flexibility since joint stability refers to the ability of the surrounding muscles and ligaments to maintain the proper position of a joint. Therefore, the definition pinpointing flexibility centers on the ability to stretch, making the chosen answer the most precise and relevant in context.