Teacher:In this task, you're given an article, a question which often contains a blank and four options (associated with "A", "B", "C", "D"). Your task is to find the correct answer (from the given options) for the question from the given article and return one of the options from "A", "B", "C", and "D". Do not generate anything else apart from one of the following characters: "A", "B", "C", "D". There is only one correct answer for each question.
Teacher: Now, understand the problem? Solve this instance: Article: Range At present,there are five network firms---China Telecom,China Unicom,Jitong Communications,China Netcom and China Mobile---that are allowed to operate IP services in China.Each company has its advantages in service. Charge As the Ministry of Information Industry co-ordinates,the charges of IP calls of the five companies are the same,0.30 yuan per minute for DDD calls.4.80 yuan per minute for IDD calls,2.50 yuan for calls from the mainland to Hong Kong,Macao,and Taiwan,and 1.50 yuan from Shenzhen to HK,Zhongshan and Zhuhai to Macao.IP callers don't enjoy discounts on holidays. China Telecom has the widest coverage.All cities in China with telephone access and most countries in the world are open to China Telecom's IP card. China Unicom's IP card can reach 29 cities nationwide and more than 130 countries and regions worldwide.Jitong IP can access 12 cities in China and over 70 countries and regions worldwide. China Netcom's IP card can reach 14 cities in China and 149 countries and regions in the world. China Mobile's IP card is open to only six cities nationwide but can access more than 200 countries and regions worldwide. Voice quality China Telecom realizes its IP service by the public Intermet,therefore net congestion and voice delay may sometimes disturb conversations.The other four companies have their private data networks,which help to increase transmission speeds and improve voice quality. Other services China Telecom,Jitong and China Mobile offer account transfer services.Users can transfer the remaining sum of money on one card to another card. Jitong and Netcom Link their services with bank cards.One can enjoy IP's service without an IP card.Bank card users can make IP phone calls with their bank card numbers,so they needn't buy new IP cards and remember the new numbers again and again. As for customer service,China Telecom,China Unicom and China Mobile provide free hot line service,while Jitong and Netcom charge for their services.
Question: Which of the following is mentioned in the passage?
Options: (A) China Unicom charges IDD calls more than the other four firms. (B) China Mobile's coverage is the least of the five firms. (C) China Telecom accesses many more cities nationwide than the other four. (D) China Netcom is the only one to be allowed to operate IP service.
Student:
C