阅读下列短文，从下面每小题的A、B、C、D四个选项中选出最佳选项。

    A Bite of China, the seven-part documentary (纪录片) introduces Chinese food through the geography, history and culture.

A Bite of China is fill of &eat pictures of food, from expensive food to local food. The documentary shows Chinese food culture and how to make the delicious food.

    How to make dishes is only one part of food culture. The program tries to bring something new by showing more cultural elements (元素) about dishes, such as eating habits, and people's life. For example, one part tells China's history of rice growing. It explains why rice is the main food of the southern Chinese, while the northern ones mainly eat wheat flour (面粉).

    And a part about pickles(腌制食品) tells about a woman in Beijing. She returns to her hometown in Jilin and makes pickles for the first time for her lonely mother.

Another part shows happy moments of sons and daughters making New Year cakes after they return home from different cities to celebrate with their lonely parents in Zhejiang.

A Bite of China also shows social changes when showing food culture. For example, some members of a family work outside but leave the old in their hometowns - in this case, food can make people remember the happy time.

小林今年九岁了，三岁时妈妈因重病去世了，他和爸爸相依为命，后来，爸爸认识了小陈，还和她结了婚。现在他又有了一个美满的家，又有了一个疼爱他的妈妈。小林和父亲、继母组成的家庭是（    ）

随着互联网的普及、网上支付的不断完善，加上物流业的配套建设，网上购物方式获得更多人群的青睐。据统计，2015年上半年网上支付交易额同比增长80.92%。作为一个正在发展的产业，不仅直接产生了美术设计、网购服务、仓储、配送、系统开发等行业，而且还催生了网模、职业砍价师、网购推销员等新兴衍生职业。

结合材料，运用生产与消费关系的知识，分析网购这一经济现象的积极作用。