Please choose the correct solution to the question: How to perform a  barbell curl?

Solution1: 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.

Solution2: 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.

Answer format: solution1/solution2