The correct answer is A. Debbie knew that studying for her test was important; consequently, she cleared her schedule for the night.
Step-by-step explanation:
Punctuation marks vary according to the elements found in a sentence. In the case of the sentence presented this includes two main clauses joined by the linking word "consequently". This linking word similar to others such as however, therefore, thus or on the other hand, required a comma after it as they introduce another clause. Besides this, if "consequently" is used between to different clauses it is necessary to place a semicolon before "consequently" as this marks the end of a clause or sentence and the beginning of other. Considering this, the sentence that uses correct punctuation is "Debbie knew that studying for her test was important; consequently, she cleared her schedule for the night".