次のようにオプション値を取得するには、crmapisを使用します。
_serviceProxy = new OrganizationServiceProxy(serverConfig.OrganizationUri, serverConfig.HomeRealmUri,
                serverConfig.Credentials, serverConfig.DeviceCredentials);
_serviceProxy.EnableProxyTypes();
_service = _serviceProxy;
RetrieveAttributeRequest retrieveAttributeRequest =
    new RetrieveAttributeRequest
    {                            
        EntityLogicalName = EntityLogicalName,
        LogicalName = optionSetLogicalName,
        RetrieveAsIfPublished = true,
    };
// Execute the request.
RetrieveAttributeResponse retrieveAttributeResponse =
    (RetrieveAttributeResponse)_service.Execute(
    retrieveAttributeRequest);
// Access the retrieved attribute.
PicklistAttributeMetadata retrievedPicklistAttributeMetadata =
    (PicklistAttributeMetadata)
    retrieveAttributeResponse.AttributeMetadata;
// Get the current options list for the retrieved attribute.
OptionMetadata[] optionList =
    retrievedPicklistAttributeMetadata.OptionSet.Options.ToArray();
//Dictionary<int,string> LocalizedLabelDic = new Dictionary<int,string>();
List<ListItem> OptionSetItems = new List<ListItem>();
foreach (OptionMetadata o in optionList)
{
    OptionSetItems.Add(new ListItem(o.Label.LocalizedLabels.FirstOrDefault(e => e.LanguageCode == 1033).Label.ToString(), o.Value.Value.ToString()));
}
次に、listitemジェネリックcollectoinをurasp.netドロップダウンにバインドします