A drug company is testing two dosages of a new cancer drug against two different drugs that are considered options for standard treatment, and a combination of their new drug with each of the other two. The effectiveness of the drugs is measured by mean days of survival, which is a normally distributed variable. What test could the drug company use to compare all 6 drugs options at once? The participants in the study have been randomly allocated to the treatment groups and the variance of the days of survival is the same for each group. Group of answer choices 1 way ANOVA MANOVA Pearson's r Simple linear regression