Assemblies

Question

Hi, please help me with this question.

If two assemblies contain the same fully qualified class, which of the following will be true?

1) It is impossible to add a reference to both assemblies to any given assembly
2) A new root can be added to the assemblies namespace hierarchy by the use of an extern alias
3) The specific colliding name be altering by using an extern alias
4) The collision may be avoided by using a statement to provide an alias