What part of the body is being stretched if you follow these steps?

Stand tall, your feet slightly wider than shoulder-width apart, your knees slightly bent. Hold your arms out to the side parallel with the ground, and the palms of your hands facing forward. Rotate your hands so the palms face to the rear. Stretch your arms back as far as possible.
(1 point)
Responses

chest and biceps

hips and buttocks

shoulders and upper back

triceps and shoulders