Need Order by in LINQ

New to Linq.

I need to add an order by on the new  AppResourceDetails().Need to order by on arg.GroupDescription

appResourceDetails = context.AppResources                    
                        .Where(ar => ar.AppId == appId && ar.GroupId != UserDefinedReports)
                        .Join(context.AppResourceGroups, ar => new { ar.GroupId, ar.AppId }, arg => new { arg.GroupId, arg.AppId },
                        (ar, arg) => new AppResourceDetails()
                        {
                              ResourceId = ar.ResourceId,
                              ResourceTypeId = ar.ResourceTypeId,
                              ResourceDescription = ar.ResourceDescription,
                              ResourceComment = ar.ResourceComment,
                              CreateDate = ar.CreateDate,
                              ExpirationDate = ar.ExpirationDate,
                              GroupId = ar.GroupId,
                              GroupDescription = arg.GroupDescription
                        }).ToList();

Appreciated
thank you