For the comparison of body mass index (BMI) and plethysmography body composition assessment techniques, which of the following statements is correct?

Plethysmography accounts for lung volume through residual volume correction, so the difficulty of lung volume determination does not make it inferior - it is a manageable and standard part of the protocol.

BMI is a simple ratio of weight to height squared and treats all body mass as equivalent, meaning a muscular athlete and an obese sedentary individual with the same BMI would be indistinguishable by the metric. Plethysmography (air displacement plethysmography) measures body volume to calculate body density, allowing separate estimation of fat mass and fat-free mass. This makes plethysmography a far more precise body composition assessment tool than BMI.

Plethysmography does not specifically account for hydration state; techniques such as bioelectrical impedance analysis are more sensitive to hydration changes.

BMI is not superior to plethysmography in predicting percent body fat - its standard error of estimate is larger because it cannot differentiate fat from lean mass.