What type of assessment can measure a client’s body composition?

The correct answer focuses on skinfold measurements because this method specifically targets the evaluation of body composition. Skinfold measurements assess the thickness of skinfolds at various sites on the body to estimate subcutaneous fat. By measuring these folds and using specific formulas, trainers can derive body fat percentages, which is a critical component of understanding an individual's overall body composition.

Other assessment types mentioned do not measure body composition directly. Cardiovascular fitness tests gauge the efficiency of the heart and lungs during exercise, flexibility assessments evaluate the range of motion in joints and muscles, while strength evaluations determine the maximum force a person can exert in various exercises. Each of these assessments serves important purposes in fitness and health evaluations, but they do not provide insights specifically into body fat or lean mass, which is why skinfold measurements are the appropriate choice for assessing body composition.