Please choose the correct ending to complete the given sentence: Health: [header] How to get back to sleep [title] Relax your muscles progressively. [step] If you woke up and are struggling to get back to sleep, one excellent method of falling back to sleep quickly without moving or getting up is to try a technique called progressive muscle relaxation. It's easy and effective in helping people get back to sleep quickly.

Ending1: [substeps] Start with your feet, focusing all your attention on your feet. Breathe deeply, sending all your relaxation and your energy toward your feet. Ending2: Simply relax your body in gradual ways, such as gently tensing and releasing the tension in your muscles. [substeps] To do progressive muscle relaxation, sit in a comfortable position or lie on your back with your legs bent and your feet on the floor. Ending3: [substeps] Start by tensing and releasing a muscle for 5 seconds. Hold this for 5 to 10 seconds and then release it for 5 seconds. Ending4: [substeps] Start counting how many times you breathe in and out through your nose, keeping count as you close your eyes. Hold the count for 5 breaths, and then immediately increase your count a bit more.

Answer format: ending1/ending2/ending3/ending4