John Works as a Sales Representative for Traveldesire

John works as a sales representative for Traveldesire.com,an online travel portal.He receives a call from a Russian customer,who is not fluent with English,enquiring on holiday packages.To serve the customer's needs better,John should:

A) assume that everyone has the same experiences and treat them accordingly.
B) let the customer guide the conversation.
C) raise his tone to enhance better understanding and lay emphasis.
D) ask closed-end questions.