A new experiment evaluated the use of genetically engineered white blood cells in the treatment of patients with melanoma. Patients were divided into four cohorts where three cohorts received cells that were cultured for varying days and one cohort received genetically engineered lymphocytes. Results from the ANOVA were significant (p=0.003). using the Bonferroni method. How many possible post hoc pair-wise comparisons are there?

Group of answer choices

1 comparison

3 comparisons

6 comparisons

24 comparisons