What aspect of fitness does the CFT primarily assess?

The Marine Corps Combat Fitness Test (CFT) primarily assesses a balance of physical strengths and endurance, which is accurately captured in the correct choice. The CFT is designed to evaluate a Marine's overall physical readiness by incorporating various elements that reflect both strength and endurance components.

For instance, the CFT includes events such as the maneuver under fire, which tests physical endurance, agility, strength, and coordination, and other performance measures that are vital for combat readiness. This comprehensive assessment helps ensure that Marines possess the necessary capabilities to perform effectively in a range of operational scenarios.

In contrast, the other options focus on narrow aspects of fitness. Limiting the assessment to either muscular strength, cardiovascular fitness, or flexibility alone would not provide a complete picture of a Marine’s functional fitness. The CFT's holistic approach allows for better preparation for the diverse physical demands faced in real-world situations.