根据短文理解，选择正确答案。
Many years ago, a young woman doctor named Jessie received a present-“a parrot” at her birthday party. She was always busy in the hospital and spent little time with the parrot. So over time the parrot developed a bad attitude(态度).
It got to the point that every word out of the bird's mouth was obnoxious. Sometimes the parrot even shouted at Jessie. She tried and tried to change the bird's attitude by saying only polite words, playing soft music and anything else she could think of to “clean up” the bird's attitude.
Finally, Jessie was angry and shouted at the parrot. The parrot shouted back. Jessie lost her temper and shook the parrot. The parrot became even more rude. Jessie threw the bird into the fridge angrily. For a few minutes the parrot kicked and screamed. Then suddenly there was total silence.
Fearing that she'd hurt the parrot, Jessie quickly opened the door to the fridge.
The parrot walked out onto Jessie's arms and said “I believe I may have offended(冒犯) you with my rude language and actions. I am so sorry for what I said and did just now and I will do everything I can to correct my rude attitude.”
Jessie couldn't believe the change in the bird's attitude.
As she was about to ask the parrot what had made such a change in his attitude, the bird spoke-up, very softly, “May I ask what the turkey did?”
，三位同学甲、乙、丙在研究此函数时分别给出命题：
对任意
恒成立.