阅读下面短文，完成相关任务。
Microsoft has stopped providing service for Windows XP since April 8,2014. Microsoft has provided support for Windows XP for the past 12 years. 【1】The computers that use the XP system are not as safe as before.

The "demise"(停用) of Windows XP will have the greatest influence on China because it has about 210 million XP users, who make up about 70.percent of the PC market in the world. Microsoft's decision to "kill" Windows XP, a product with hundreds of millions of users, has a certain purpose to show its strong position in the operating system market.
At the same time, the "death" of XP has created opportunities for China's IT companies to grow and develop. China can break the monopoly(垄断)of international IT giants and protect the internet security(安全) by having information technology and a policy that encourages innovation.
把划线部分翻译成汉语：                                            
根据短文内容回答第2—4题：
In which year, Windwos XP started to provid support?
According to the passage,how many XP users are there in the world?
How can China break the monopoly of international IT giants and protect the internet security? 
What is the main idea of the passage?   

A．How to protect our XP system?

B．How to change your computer?

C．Why did Mirosoft stopped providing service for Windows XP

D．The influenc about the “demise” of Windows XP.