Answer:
D. Making eye contact and smiling when Mill talks.
Step-by-step explanation:
Since Mr Burns is described as friendly, warm and non verbal in expression, it shows that he only smiles and makes contact with Mill .
Jonathan Mill is just a guest relations executive who has nothing to do with whatever work Mr. Burns might be doing, Burns cannot be discussing any work related stories with him on the first meeting day.
If Mr Burns would like to know more about Mill and build a personal rapport with him, that could best be done by talking to him, which from the information we have, Mr Burns didn't do.
Moreover, he cannot share his other hotel experience with Mill non verbally, which makes option A the only correct option.