<prompt> In which the following head and neck cancers, is lymph node metastasis least commonTongueBuccal mucosaHard palateLower alveolus  <response>: LN metastasis is most common in : CA tongue Floor of mouth Lower alvealus Buccal mucosa Upper Alveolus Hard palate lip Ref: Bailey and love 27th edition Pgno : 764-765, 