<em>The right answer is letter C: When you have finished, clean up your area</em>. This sentence starting with "when" as a relative pronoun supposes a dependent clause will be separated from an independent one by a comma "clean up your area".
Option A follows a standard structure where the dependent clause follows the independent one; option B shows <em>"cleaning up"</em> as a detail for "finishing" as the subject of the sentence; and option D uses "cleaned" as an adjective after a modal verb "should".
<h3><u><em>Perhaps the most common goal in statistics is to answer the question: Is the variable X (or more likely, X 1 , ... , X p ) associated with a variable Y, and, if so, what is the relationship and can we use it to predict Y?
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<h3><em>Nowhere is the nexus between statistics and data science stronger than in the realm of prediction—specifically the prediction of an outcome (target) variable based on the values of other “predictor” variables. Another important connection is in the area of anomaly detection, where regression diagnostics originally intended for data analysis and improving the regression model can be used to detect unusual records. The antecedents of correlation and linear regression date back over a century.</em></h3>
'Exert' means to apply force on influence over something else, this can be in a negative or positive way. In this quotation, it means that language, if used correctly, has the ability to express a 'hidden power'. It's also worth mentioning that the simile is relevant as the moon has an influence on the level of tides on Earth.
