Which of the following is NOT a component of fitness?

• A. Cardio respiratory endurance
• B. Reaction Time
• C. Muscular endurance
• D. Flexibility

Answer: (B)

Fitness is typically described by health‑related components that show how the body supports sustained activity and movement: cardiorespiratory endurance, muscular endurance, and flexibility. Cardiorespiratory endurance is the body's ability to sustain aerobic activity over time, Muscular endurance is how long a muscle or muscle group can perform repeated contractions, and Flexibility is the range of motion around the joints. Reaction time, on the other hand, is a skill-related attribute that describes how quickly you respond to a stimulus. It matters for performance and safety but isn’t one of the health‑related fitness components used to describe overall physical fitness. So, reaction time is the one that doesn’t fit as a component of fitness in this context.