Final answer:
Athletes have the highest rate of ACL injury due to the demands of their sports, which include movements that put significant stress on the knee ligaments.
Step-by-step explanation:
The patient population that has the highest rate of ACL (anterior cruciate ligament) injury is c) Athletes. The nature of athletic activities, which often involve sudden stops, jumps, and changes in direction, increases the risk of straining, overextending, or tearing the ACL. While other groups such as the elderly, children, and pregnant women may also experience ACL issues, athletes, especially those participating in high-demand sports like soccer, basketball, and football, are at a significantly higher risk.