The addition of a group that does not use the drink additive but adds a similar-looking substance that they think is the additive would dr. bloedorn address what threat to internal validity?

The similar looking substance is acting as a placebo. In other words, a substance that will not have any therapeutic effects on the patient.

A placebo is currently used in the treatment of people with hypochondria, which is a psychological condition in which a person is under a constant belief that he or she is having an illness.

By adding this alternative substance (or placebo), Dr. Bloedorn is trying to address the individual's condition of hypochondriasis.

a) they had recently endured the tyranny of the british king, parliament, and its royal

answer; obey the closest relative's wishes;