查询职称为讲师的姓名，年龄和性别，正确的语句是？ A.
db.teachers.aggregate([
{project:{"name":1,"age":1,"sex":1,"_id":0}}
])
B.
db.teachers.aggregate([
{project:{"name":1,"age":1,"sex":1}}
])
C.
db.teachers.find("prof":"讲师",{"name":1,"age":1,"sex":1}) D.
db.teachers.find({"prof":"讲师","name":1,"age":1,"sex":1})