根据以下材料，回答26-30题
The rivalries among the tech industry's giants have often resembled a "Game of Thrones", in which companies such as Facebook, Google,and Apple constantly try to invade one another's online kingdoms.On February 19th Facebook took a dramatic step to defend its turf, saying it would pay $19 billion for Whats App, a messaging service that had also attracted the attention of Google and almost certainly other suitors.
The deal marks the coming-of-age of messaging apps, which let people send text messages and share photos and other stuff without incurring charges from telecoms firms.These apps have benefited from two profound trends that are transforming the technology landscape.The first of these is the rapid growth of web-connected smartphones, which has allowed WhatsApp and its rivals to spread like wildfire.Announcing the deal Mark Zuckerberg, Facebook's boss, said Whats App had reached 450m users much faster than any other web service.It has also made itself addictive：72% of its users are active on it every day.And the viral nature of its appeal means it has achieved all this without spending a penny on marketing.
The second trend behind Whats App's success is the dramatic decline in the cost of building start-ups.Thanks to things such as cloud computing, which lets young firms buy vast amounts of cheap computing capacity, entrepreneurs can create globe-spanning businesses on shoestring budgets.Whats App has just 32 software engineers, which means that eaeh one supports some 14m users.And the volume of messages it is handling is said to be the equivalent of all the SMS messages transmitted by the world's telecoms companies.
Indeed,Whats App's success in many ways mirrors that of Facebook itself, which came from nowhere to dominate social networking.Recently,however, Facebook has been losing some of its cool, especially among younger users.That may explain why the famously paranoid Mr. Zuckerberg is willing to pay a king's ransom for a company that might ultimately eclipse his own creation.
But does the whopping price tag for Whats App make sense? Assuming it keeps adding users at its current rate of 1 m a day—and they end up paying for its service—it could generate hundreds of millions of dollars of revenue.Much will depend on how well Mr.Zuckerberg gets on with Jan Koum, the boss of Whats App, who is joining Facebook's board and will run the app as an independent business. Mr.Koum, who has a well-known aversion to collecting people's data and plastering advertising over his App, seems an odd bedfellow for Facebook.But the deal was clearly one that he couldn't refuse.
JanKoum, according to the text, is probably_____

A that rare bird working against techgiants.

B an opponent of tracking users'information.

C a strange partner for his unusual work style.

D an advocate of apps with real-time ads.