Flexibility, defined as the range of motion in joints and the extensibility of muscles, is a critical element of health-related fitness, crucial for physical well-being and injury avoidance.
- Option (a): "Action" is not recognized as a health-related fitness component.
- Option (b): "Balance" is classified as a skill-related fitness component.
- Option (d): "Co-ordination" also falls under skill-related fitness.
Therefore, option (c) accurately identifies flexibility as a component of health-related fitness.