Given the task definition and input, reply with output. 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 get rid of back fat [title] Step up the cardio. [step] For best results, exercise for at least 30 minutes at a time, three to five days a week. [substeps] These cardio activities are particularly effective for getting rid of back fat. <sep> (A) Aim for about thirty minutes an hour, five days a week. Aim for 30 minutes in between cardio sessions for optimal results. (B) They will burn calories and strengthen your back muscles: rowing, boxing and swimming. Other cardio exercises to include are: running/jogging, walking, biking, using the elliptical or dancing. (C) In fact, intense cardio exercise (like aerobic exercise) can reduce the progression of a variety of diseases. This can both improve your metabolism and add little, if any, to your back fat intake. (D) A vigorous and appropriate cardio regimen can effectively prevent back fat caused by joint problems. Try cardio that involves running, cycling, or, , if possible, jogging.
B