How do you identify like terms?
Like terms are separated by
or

Step-by-step explanation:

Terms are separated by addition or subtraction in an expression. Recall that a monomial is a single term, a binomial has two terms, a trinomial has three terms and a polynomial has many tearms

In statistics, blocking refers to the arrange of experimental units in groups, where each subject have a specific characteristic in common, for example the gender.

So, by dividing the sample into blocks, where each block is almost independent one to another, it helps to manage studies with multiple variables, which it can imply a higher difficulty when the research have to analyse results, because they need to demonstrate or reject a specific relation between variables, if there are too many, it's better to divide the sample in to specific groups, classified depending on their particular characteristics which make them independent, that is, one group doesn't affects other groups.

Using this method in the experimental design, researches are assuring the reliability of the results. Therefore, the correct option is B: blocking has the purpose of controlling multiple variables in an experiment.