Noah Is Examining the Effects of Taking the Medication Lactaid

Noah is examining the effects of taking the medication Lactaid, which is for people who are lactose intolerant. Noah is curious if prolonged use of the medication increases tolerance of lactose. Noah randomly assigns lactose-intolerant participants to one of two groups. One group will ingest dairy but will be given a placebo pill (no Lactaid) . Noah is aware that for these participants, ingesting dairy without Lactaid may result in digestive issues. Noah should be concerned about the:

A) psychological harm of his participants.
B) physical harm of his participants.
C) economic harm of his participants.
D) legal harm of his participants.