听力原文： There is an art exhibition here on campus which ties well of discussions we've had about folk art. it's an exhibition of wildlife art calendars from about a hundred years ago. Like most other folk art, the calendar pictures were not considered to be art in their own days. People just thought of them as a way of decorating a practical object. In fact, the calendar pictures were originally painted as advertising for various companies that made hunting or fishing produces, like guns or fishing rods. The calendars were handed out free to customers to thank them for their business. Most people just hung the calendars on their wails where the pictures faded in the sun and then tore the pictures off the calendar as each month passed. As a result, collectors today place of a lot of value on calendars that are complete and in good condition. Even though the people who used the calendars didn't regard them as art, the original paintings the prints were made from were often of good quality. In fact, many famous wildlife painters created calendar art at some point in their lives. To them, it was way of getting a work reproduced and showed around. One aspect of the exhibit that I find very interesting is the way these pictures reflect changing attitudes toward wildlife. The pictures in the exhibit often portray the thrill and adventure of hunting rather than any particular concern for wildlife preservation. But most of today's wildlife art shows animals in their natural surroundings without any humans in the scene. This modern wildlife art appeals to large numbers of nature lovers, even those who oppose the practice of hunting.
What is the talk mainly about？

A. How artists gained fame.
B. A schedule of art exhibits.
C. One form. of folk art.
D. The preservation of old paintings,