Butan-2-ol cannot be directly converted to 1,2-dibromobutane. The conversion can be carried out in two stages by first converting butan-2-ol into x, which is then reacted with bromine. What is x?
1) 1-bromobutane
2) 2-bromobutane
3) 1,3-dibromobutane
4) 1,2-dibromobutane