In this task, you are given a context and four options. Each option is a suggested ending for the context. You should read the context and pick the best ending for the context. Please answer with "A", "B", "C", and "D".

[header] How to perform a weighted squat [title] Begin your warmup by running on a treadmill. [step] Running on a treadmill before squatting is a great way to get the blood flowing into your legs. This allows you to perform your workout better. <sep> (A) [substeps] Start at a low speed setting and fast walk, until you feel your heart rate has started to increase. Increase the speed, until you reach a comfortable jog. (B) However, be sure to avoid the spin, giving your legs a much bigger impact if you do the workout outside of a treadmill. [substeps] Before you get on a treadmill, make sure you're hydrated. (C) [substeps] Start on your right foot and lift one foot up and rest on the floor. Lift one foot off the floor, and roll it underneath the other. (D) Start by getting off the treadmill and hiking up a hill so that your feet don't get sore. [substeps] Warm up your muscles by standing with a few inches of space between your feet and moving into the wall.
A