Please choose the correct ending to complete the given sentence: Sports and Fitness: [header] How to work out your upper chest [title] Perform a guillotine press to work your pectoral muscles. [step] Load weights onto both sides of a barbell. Lie on your back on a flat bench with your feet flat on the floor or feet flat at the end of the bench.

Ending1: Press your chest inward until your sternum and sides are tilted just slightly toward each other. Smooth out your pectoral muscles by keeping your stomach blades raised and using both of them to steadily push the barbell forward and upwards. Ending2: Raise one arm out to your chest as high as you can and hold it there for 2 seconds. Do this for each bicep or triceps. Ending3: Lift the barbell slowly up in the air and hold for a few seconds. Then slowly lower back down on the barbell slowly, squeezing the gluteal muscles in your upper chest muscles. Ending4: Use your core strength to hold your lower spine in a neutral position. Hold the bar with an overhand grip with your arms slightly more than shoulder-width apart.

Answer format: ending1/ending2/ending3/ending4