Answer:
The correct answer is remembering a customer's name.
Step-by-step explanation:
Talking about a positive impression on a costumer, letter A is incorrect because the customer might believe that informal language is not proper for the restaurant. Foreign names might sound difficult and strange so customers could get lost while ordering. Formal language can create a barrier between customer and the staff, who should find the balance between formal and informal. Remembering a customer's name would give a sense of familiarity and might help the customer feel more comfortable and in a friendly environment.