[SerializableAttribute()] 
public class FieldOption 

public class FieldOptionHandler
{
   public string AddOption(string fieldID, string title, string value)
   {
       FieldOption opt = new FieldOption();

       opt.FieldID = fieldID;
       opt.Sort = FieldOption.MaximumSort(FieldID) + 1;
       opt.Title = title;
       opt.Value = value;
       opt.IsDefault = false;
       
       opt.Save();        
 
       return opt.ID;
   }
}