RetrieveOptionSetRequest Class

// Use the RetrieveOptionSetRequest message to retrieve  
// a global option set by it's name.
RetrieveOptionSetRequest retrieveOptionSetRequest =
    new RetrieveOptionSetRequest
    {
        Name = _globalOptionSetName
    };

// Execute the request.
RetrieveOptionSetResponse retrieveOptionSetResponse =
    (RetrieveOptionSetResponse)_serviceProxy.Execute(
    retrieveOptionSetRequest);

Console.WriteLine("Retrieved {0}.",
    retrieveOptionSetRequest.Name);

// Access the retrieved OptionSetMetadata.
OptionSetMetadata retrievedOptionSetMetadata =
    (OptionSetMetadata)retrieveOptionSetResponse.OptionSetMetadata;

// Get the current options list for the retrieved attribute.
OptionMetadata[] optionList =
    retrievedOptionSetMetadata.Options.ToArray();