Unable to call a library from other in MEF

I have 3 class libraries, LibA, LibB & LibC. These libraries have defined classes A, B & C respectively.

class C
{
  public IEnumerable<X> FuncInC()
  {      
    return something;
  }
}

LibC is added as a reference in LibB. And class B uses class C. Using MEF, I have exported class B from LibB.

[Export(typeof(InterfaceForB))]
class B : InterfaceForB
{
  public IEnumerable<X> FuncInB()
  {
    return new C().FuncInC();
  } 
}

In class A, i am using the exported class from B, as follows.

public class A : InterfaceForA
{
    [Import(typeof(InterfaceForB))]
    private InterfaceForB _b;

    private CompositionContainer _container;

    public A()
    {
      var _catalog = new DirectoryCatalog(System.IO.Directory.GetCurrentDirectory());
      _container = new CompositionContainer(_catalog);
      _b = _container.GetExportedValue<InterfaceForB>();
    }

    public IEnumerable<X> FuncInA()
    {
      return _b.FuncInB();
    }
}

When i run FuncInA(), it raises FileNotFoundException with the following details:

"Could not load file or assembly 'LibC, Version=1.0.0.0, Culture=neutral, PublicKeyToken=null' or one of its dependencies. The system can开发者_如何学JAVAnot find the file specified."

Note:

1. LibC reference exists in LibB, and it is build without errors.
2. And all the assemblies (output dlls in this case) exist in the the same folder.
3. If I comment the code "return new C().FuncInC();" in FuncInB() definition, & return a dummy object, it works without errors. The problem is because of the reffered LibC use.

In the LibB References shown in the solution explorer, right click on LibC, "properties", set "Specific Version" to "False".

Or better yet, delete the binary reference and replace it by a project reference (assuming that LibC is in the same solution as LibB).