下列选项中格式正确的是（）。

A. varperson={"username":"jack",age:23,'sex':true};
B. varperson={"username":"jack","age":23,'sex':true};
C. varperson={"username":"jack","age":23,"sex":true};
D. varperson={'username':"jack",'age':23,'sex':true};
E. varperson={username:"jack",age:23,sex:true};