The sentence that is punctuated correctly is sentence D: The new school directory is out; it contains the names and phone numbers of all the students in the school. The first and the second clauses are independent clauses, and it would be incorrect to separate them by only using a comma if there are no coordinating conjunctions between both, For this reasons, the correct way to separate them is by using a period or a semicolon. In addition, it is not correct to use a comma to separate a list that only has two elements as in the case of list that includes "names" and "phone numbers".