Which statement best describes the purpose of randomization?

• A. It ensures equal distribution of animals across groups
• B. It randomizes data collection order
• C. It selects the statistical test
• D. It ensures uniform dosing

Answer: (A)

Randomization helps prevent bias by making groups comparable. When animals are assigned to different treatment groups by chance, both the known variables (like age, weight, sex) and the unknown factors that could influence outcomes tend to be spread evenly across groups. This balance means that differences in results are more likely due to the treatment itself rather than preexisting differences between the animals. That’s why the statement about equal distribution of animals across groups captures the essential purpose of randomization. The other ideas describe separate ideas: ordering data collection, choosing which statistical test to use, or how dosing is administered are controlled by other parts of the study design and do not by themselves ensure that the groups are comparable.