Which of the following expressions is correct when a customer comes to the company？

Which of the following expressions is correct when a customer comes to the company？
A.I 'll contant our boss，please wait a moment.
B.If the boss is not available，politely make an appointment for anither time.
C.Welcome to our company.
D.I 'll show you to the reception room first.
正确答案：I 'll contant our boss，please wait a moment.If the boss is not available，politely make an appointment for anither time.Welcome to our company.I 'll show you to the reception room first.