题目

Twelve-year-old Paul Crossnickle has lived as a hero for six years now. It wasn’t until he wrote a composition for a recent class project, however, that he got the recognition he should have got. On July 27, 1991, Paul saved his three-year-old sister Julie from drowning in the family swimming pool. When he found her, he jumped in, pulled her off the bottom and brought her to the ground. Their father was trying to bring Julie to life when fire fighters arrived. She survived without serious injury. Last month, in Paul’s seventh-grade language arts class at Juniper Elementary School, teacher 如图所示，满面足a﹤0，b﹥0的函数的图像是 [　　]