<human>: Objective: How to perform a  barbell curl?

Which of the following solutions is more sound in terms of naive physics reasoning?

OPTIONS:
- Stand straight, with the barbell held in the hands, arms resting. Bend your arms at the elbow joint, to lift the barbell to a flat angle, and then lower it back down and repeat.
- Stand straight, with the barbell held in the hands, arms resting. Bend your arms at the shoulders, to lift the barbell to a flat angle, and then lower it back down and repeat.
<bot>: Stand straight, with the barbell held in the hands, arms resting. Bend your arms at the elbow joint, to lift the barbell to a flat angle, and then lower it back down and repeat.