Which is/are true of lactase deficiency/lactose intolerance? I. a very small portion of people are lactase deficient, which leads to milk allergy II. the majority of humans people have lactose intolerance; lactase deficiency is quite common, even though enzyme deficiencies in general are not common III. it's possible for people with lactose intolerance to consume lactose-containing products if they take supplemental lactase immediately before or along with the meal Olonly OI and III O ll only O II and III