Please choose the correct ending to complete the given sentence: Sports and Fitness: [header] How to stretch for achilles tendonitis [title] Do heel drops with straight legs. [step] Stand on the edge of a step. Position yourself so that the balls of your feet are on the edge of the step and your heels are floating in air but parallel to your toes.

Ending1: Bend your right knee and hold on to your left ankle with your right hand, then squat down until your knees hit the ground, keeping your feet on the last step you have for stability. [substeps] Try your toe drops on a hill. Ending2: Tense your gluteus muscles to form an " l " shape. Hold the stretch for two to three minutes. Ending3: Keeping your legs straight, but without your knees being locked, flex your ankle and feet slowly so your whole body lifts up. [substeps] Once you get as high as you can, bring your body back down, so that your feet return to their horizontal starting position. Ending4: Bent over at a 90 degree angle, place both palms facing downward at shoulder height. Bring your knees up toward your chest until they are on your toes, then bring them down and lock your knees.

Answer format: ending1/ending2/ending3/ending4