You should use a gracious, trusting tone in a routine adjustment letter
a. when writing to an internal reader rather than an external reader.
b. to balance the negative language used to describe the claim.
c. to avoid losing the customer's goodwill and confidence.
d. when you have decided not to grant the reader's request.
e. when you want to persuade the reader to do as you ask.
Answer: to avoid losing the customer's goodwill and confidence.