<prompt> Serum retinol below which level is considered to be an indicator for xerophthalmia?1 mcg dl5 mcg dl10 mcg dlNone of the above  <response>: The following are the prevalence criteria for determining xerophthalmia problem: Criteria Prevalence in 6 month to 6 years population Night blindness 1 Bitots spots 0.5 Corneal xerosisulceration 0.01 Corneal ulcer 0.05 Serum retinol 10 mcgdl 5 Ref: Park 22nd edition, page 571 