Refer to the passage below and then answer the question afterwards in the same language as the passage:

Passage: On February 21, 2014, version 4.5 entered beta stage. On the same day, Microsoft announced that starting with this version, Windows XP would not be supported. Older versions would continue to receive automatic virus definition updates until July 14, 2015 (afterwards the users of older versions may continue to manually update definitions using Microsoft's site).

Question: Beta stage 4.5 was entered in what year?
2014