Pushing against a resistance band is an example of resisted protraction on a Pilates apparatus.
An example of assisted retraction and resisted protraction on a Pilates apparatus would typically involve movements that engage the shoulder blades (scapula). Protraction occurs when the scapula moves forward, as when pushing against resistance, while retraction involves pulling the scapula towards the vertebral column. Therefore, the correct answer is pushing against a resistance band, which is an example of resisted protraction as it involves moving the shoulders forward against resistance.