I am trying to figure out the sentence that does not belong to this paragraph.
The researchers developed three criteria for the test subjects. The test subjects needed to be women because the drug was marketed to them. Also, they needed to be between the ages of 21 and 35. Having subjects during the prime childbearing years would eliminate age related causes for drug failure. Another cause of drug failure might be incorrect use. Finally, all subjects need to have abstained from illegal drug use. Prior drug use can interfere with the drug's efficacy
I thought it would be the second sentence, but apparently this is wrong. Which one would it be and why then?