Hepatitis C is a blood-born viral infection that causes liver inflammation and infection that, over time, can lead to liver disease. There is no vaccine against this strain of hepatitis, so preventive measures are the only management techniques. One of the ways hepatitis can be transmitted is by use of improperly sterilized tattoo equipment or contaminated dyes, which in turn has led to more stringent sterilization requirements for commercial tattoo parlors. Researchers at the University of Texas Southwestern Medical Center examined the medical records of 113 patients who had a tattoo to see whether these sterilization requirements at commercial parlors are reducing the proportion of hepatitis C among those with tattoos, compared to those who get tattoos elsewhere. Data are summarized in the following table.

	Commercial parlor	Elsewhere	Total
Has Hep-C	10	15	25
Does not have Hep-C	60	28	88
Total	70	43	113

Is a theory-based approach appropriate to evaluate the relationship between the incidence of hepatitis C and the type of tattoo parlor?

Yes, since 113 is larger than 20.

Yes, since 10, 15, 60, 28 are all at least 10.

Yes, since 70 and 43 are both greater than 20.

No, since the number with hepatitis C in each group is less than 20.