becky works the first deck at a hotel.what is the best way to greet mr. smith, a regular guest of the hotel?

a. " good evening, sir
b. " good evening. great to see you. how may i help you?
c. " good evening, mr smith. great to see you again. how may i help you?
d. " good evening, Mr Smith. Great to see you again. How may i help you?"​