<prompt> Stage X3B refers to the following in the classification of vitamin A deficiency:Night blindnessCorneal xerosisConjunctival xerosisKeratomalacia  <response>: d. KeratomalaciaRef: Nelsons 20e p 3 IB-320, Ghai Be p 111-112WHO classification of Vitamin A deficiency:IndicatorCategoryNight blindnessXNConjunctival xerosisX1ABitots spotsX1BCorneal xerosisX2Corneal ulcerationX3AKeratomalaciaX3BXerophthalmia-related corneal scarsXS 