CORRECTION :
A.
- the unique job you can find at Google is being in charge of employees' well-being (l6-7)
- Google spends so much on their employees so that they don't try to get another job in Silicon Valley (l11-14)
B. Twain means that work doesn't have to be boring, it can be pleasant and fun. It also depends on the environment and the working conditions.
C. Google is setting a new trend that will probably inspire other companies.