听力原文：In the summer, most people tend to lose weight only to see it return in the winte

听力原文： In the summer, most people tend to lose weight only to see it return in the winter. This temporary weight loss affects the metabolism for most people in a negative way since it has been clinically proven that a steady, level metabolism rate is preferred to one that fluctuates up and down over different seasons of the year. Therefore, in order to maintain this steady weight loss, a new product has surfaced on the market in the form. of a regulating wristwatch. Now you may think to yourself, there are plenty of weight watching wristwatches available in the market today. What makes this product different from any other？ Unlike most conventional weight regulation wristwatches, this watch tells you when you are burning the most calories in your day and what chemicals your body is most deficient in. Also, this new product does not only regulate weight loss but also helps regulate the optimal mechanisms to replenish the necessary minerals and vitamins necessary to sustaining a healthy balanced diet.

Who is most likely talking？

A．A salesperson.

B．A fitness instructor.

C．An overweight person.

D．A physician.