When making a self-introduction, which behavior of the following is not proper?（）

When making a self-introduction, which behavior of the following is not proper?（）
A.Speak in an arrogant voice and don’t exaggerate　oneself
B.Speak with a smile or other expressions on face when making the self-introduction
C.Speak sincerely about one’s information
D.Speak in a low voice and lower head
正确答案：Speak in a low voice and lower head