When you are meeting your coworkers. Normally, HR manager or head of office will introduce and welcome you. Which of the following introduction speech is not appropriate?
A、It's my pleasure to extend a cheerful welcome to you all!
B、On behalf of my colleagues, I wish you all a convivial welcome. 
C、Hello, how are you doing today?
D、Luckily the weather has aligned with our wishes. The sun and I bid you a warm welcome.