If someone told you they had lactase persistence A. you could offer them some nice cheese to go with their wine, but you would expect they would turn it down because they would likely suffer mild to moderate flatulation
B. you could bake them a cheesecake, and if they liked sweets, they would enjoy eating it.
C. they would likely be of non-European ancestry and do not believe that foods like ice cream (even mint chocolate chip) should ever be consumed
D. they would suffer severe cramps and diarrhea if they ingested the homemade yogurt you made for them