Which of the Following Is the Primary Interest of Designing

Which of the following is the primary interest of designing a randomised block experiment? $\begin{array}{|l|l|}\hline \text { A. } & \text { Reduce the variation among blocks. } \\\hline \text { B. } & \begin{array}{l}\text { Reduce the within-treatments variation to more easily detect differences among the } \\\text { treatment means. }\end{array} \\\hline \text { C. } & \begin{array}{l}\text { Increase the between-treatments variation to more easily detect differences among the } \\\text { treatment means. }\end{array} \\\hline \text { D. } & \text { Increase the total sum of squares. } \\\hline\end{array}$