Please choose the correct ending to complete the given sentence: Sports and Fitness: [header] How to tone your arms with yoga [title] Ease into downward dog. [step] One of the most common poses in yoga routines is downward dog. This is a great exercise to tone your arms.

Ending1: Before you start, begin by lying on the floor or on a yoga mat with your knees bent. [substeps] Take one knee to one side while keeping your feet firmly on the ground. Ending2: If you're comfortable doing this, go for it. [substeps] Start in downward dog position, where you're with your rear in the air and your back straight. Ending3: You can do downward dog like this, or you can rock and roll back and forth or swing your legs forward. The important part is getting your abs and hamstrings within their maximum size. Ending4: It requires you to keep your arms and shoulders firm and strong and overtime gives your arms great definition. [substeps] Start this position by getting onto all fours on your yoga mat or the carpet.

Answer format: ending1/ending2/ending3/ending4