题目内容：
根据下面材料，回答题。Questions 90-94 refer to the following letters.
February 18th
Ruth Walter
2921 Cypress Lane
Smithfield, UT 00375
Dear Ms. Walter,
It has come to our attention that you have failed to remit payment for service provided during the two billing periods of 7/15--8/14 and 9/15--10/14 last year.
Our records indicate that multiple bills for these periods have been sent to your address with-out reply. At this point, we are regrettably required to take stronger measures. If by April 15 we have not received payment in full, including all late fees charged, we will be forced to terminate service to your residence.
For further information about this action, or to verify the amount of your outstanding balance, please call our Customer Service Center at 1-888-555-3802, or write to the following address:
Accounts Payable Division
Northern Utah Gas & Power
55755 State Highway 16
Logan, UT 00378
February 27th
Accounts Payable Division
Northern Utah Gas & Power
55755 State Highway 16
Logan, UT 00378
Service representative,
I recently received a notification of outstanding charges on my account. I am very confused and distressed by the situation oudined in your letter.
First of all, I am certain that I paid for all services during the two billing period in question.
The payments were on time and for the correct amount. I used your company's automated telephone billing system and paid with my credit card. I am including transaction receipts from my credit card company that list these payments and the dates on which they were processed by your company.
After I had paid then, I did receive multiple bills for the periods 7/15 --8/14 and 9/15 --10/14 as stated in your letter. I tried repeatedly to report this error to your company via the customer service email system, but I never received a response. I am also attaching copies of these e-mails for your review.
These documents clearly show that I have made all payments in a timely fashion, and I hope they will help you resolve this situation. If you have any more questions for me, please contact me by phone (555-7690) or email (rwalt79@mzmail.com).
Ruth Walter
Why did Northern Utah Gas & Power write to Ms.Walter? A．To announce recent changes to its available services
B．To notify her of a new policy regarding late fees
C．To apologize for overcharging her account
D．To inform her of penalties she may be subject to
参考答案：
答案解析：