Please choose the correct ending to complete the given sentence: Sports and Fitness: [header] How to build pectoral muscles [title] Do bench presses. [step] To do bench presses, you will need a barbell and a bench. Lie back and grasp the bar with your hands shoulder-distance apart.

Ending1: Stretch your upper arms upwards, making an outward kink with your arm. Repeat 5 times, with each arm lifted. Ending2: [substeps] Lift the barbell up and jump. Shift the arm that's on the bar backwards by extending your other arm, as if you were about to lift it. Ending3: Lift the barbell with both knees and slowly raise them up and down. Turn the barbell 90 degrees towards you, and do 10 reps with the barbell and 8 repetition. Ending4: Lower the bar all the way down to your chest and then slowly press it straight up until your arms are fully extended. Start with 3 sets of 10 reps and increase the number of reps and the weight as you gain strength.

Answer format: ending1/ending2/ending3/ending4