1.To highlight functions which one should use when programming the fixed-function pipeline in all new versions of OpenGL.
2.As newer versions are released, older versions with functionality that can be created in the newer version but faster through other methods must be deprecated but are still a part of the specification
3.OpenGL’s authors at Khronos have made many mistakes and therefore deleted various functions as they released new versions, replacing older versions and making obsolete older functionality that is re
4.None of the above