Correct option is
2016
The new version upgrade – Selenium 3.0
Removal of dependency on Selenium Core was one of the major inspirations that led to the Selenium 3.0 version upgrade.
Apart from that, Selenium used complex JavaScript framework that had its own limitations. Some of the major operations that the user wanted to simulate on the AUT became impossible. With time, testing of modern web browser became more complex and this made Selenium Core very unpopular
