What is the introduction paragraph？

What is the introduction paragraph？
A.It serves as a ' map' of the essay.
B.It is supposed to raise readers’ interest and should not be too long.
C.It is usually the first paragraph of an argumentative essay.
正确答案：It serves as a ' map' of the essay.It is supposed to raise readers’ interest and should not be too long.It is usually the first paragraph of an argumentative essay.