问题：
[单选题]In the U.S. study, young adults who had only been bullied displayed the highest ______ of mental health problems, at 36 percent, followed by those who had been maltreated and bullied, at 30 percent.
Aquantity
Bpercentage
Cdegree
[单选题]In the U.S. study, young adults who had only been bullied displayed the highest ______ of mental health problems, at 36 percent, followed by those who had been maltreated and bullied, at 30 percent.
Aquantity
Bpercentage
Cdegree
