Answer:E. Be sure treatment groups are normally distributed
Step-by-step explanation: In an experiment that main purpose of randomization is to ensure that all treatment groups are normally normally distributed to ensure that all the blocks of the population are normally distributed within the sample taken. If treatments are normally distributed most of the variables will cluster in the middle with a very small proportion skewing either left or right in a normal distribution curve. Normal distribution is a major goal of statistical samplings and in experiments.