Which LTI version should I use in my C# application to create LTI provider 1.2 Or 2.0

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C#

I need to expose one of my application's component as tool by creating LTI provider. There are several version of LTI standards like 1.0, 1.1, 1.2 and 2.0, As I am going to implement this in my ASP.net application I gone through LtiLibrary for .Net which only supports LTI 1.2. Can any one suggest me if there is any other library to support LTI 2.0 and why IMS Global release LTI 1.2 in January 2015 if they already have LTI 2.0 released in January 2014.