题目

A company began to make a new kind of dog food. A party was held to show the new dog food to everyone. People from the newspapers and TV stations were there. There was a dog at the party. He was supposed to eat the dog food and have his picture taken. The plan was to show everybody how much the dog would like the new dog food. When the time came, a plate of the dog food was set in front of the dog. Everyone looked at the dog. But there was one problem. He didn’t eat any of it. The dog didn’t like the dog food!  The boss of the company had to do something fast. All of the people we在等差数列中，、，则（  ）A．6B．8C．10D．11