What benefit does good knee flexibility provide during physical activity?

Good knee flexibility allows for greater agility and movement, which is essential during physical activity. Flexibility in the knee joint contributes to a full range of motion for various physical movements such as running, jumping, squatting, and changing directions quickly. This enhanced range of motion enables athletes and individuals engaging in physical activities to perform movements more efficiently and effectively, which can lead to improved performance and reduced risk of injury. This agility is particularly important in sports that require quick pivots or changes in direction, as it helps maintain balance and coordination.

While the other options mention benefits related to muscle soreness, metabolic rate, and cardiovascular health, they do not specifically highlight the advantages that good knee flexibility has on agility and movement efficiency during activity, which makes option B the most relevant choice in this context.