A、He prefers to buy products recommended by advertisers. B、He prefers to buy products recommended by professionals. C、He prefers

Tonight, I’ll be specifically talking about wordcof-mouth advertising. As we all know, billions of dollars are spent on advertising every year.
    Well, do you prefer to buy products recommended by an advertiser or your friends? Personally, I prefer the latter, because I trust my friends. So, wordcof-mouth advertising happens when a person tells another person about the good experience with a product or service. That second person then tells another friend, family member, or colleague. By contrast, traditional advertisers talk about how good their products are. Usually, they say things like "Studies show that our products are the best. ", or "Everyone loves our products. ", but it can sound insincere or unconvincing. And some statistics also prove that wordcof-mouth advertising is more reliable and effective.
    According to a new study from NOP World, 93％ of people believe wordcof-mouth is the most reliable way to find out information about products and services, 70％ of people are affected by it, 37％ will buy it or try it, 24％ will consider it and merely 9％ will avoid it.
    So, it’s obvious that wordcof-mouth advertising has many advantages like high credibility, low costs, great reach and high efficiency. Do you agree with me? And the main reasons for the wide popularity of wordcof-mouth advertising are also apparent. Socializing and networking have now made people closer and closer. So relatives and friends are simply accessible over the net.
    Questions 13 to 15 are based on the passage you have just heard.
    13. What does the speaker say about purchasing products?
    14. What do we learn from the new study of NOP World?
    15. What is the main reason for the wide popularity of wordcof-mouth advertising?