<prompt> The first sign of Vitamin A deficiency isConjunctival xerosisCorneal ulcerKeratomalaciaBitots spot  <response>: Modified classification WHO Xerophthalmia XN: Night blindnessXIA: Conjunctival xerosis XIB: Bitots spotsX2: Corneal xerosisX3A: Corneal ulcerationkeratomalacia less than 13rd corneal surfaceX3B: Corneal ulcerationkeratomalacia equal to or more than 13rd corneal surface XS: Corneal scarXF: Xerophthalmia fundus. 