Which One of the Following Is the Best Example of Summative

Which one of the following is the best example of summative assessment?

A) Ms. Vickery gives her social studies students a test at the end of a unit to determine how well they have learned the material in the unit.
B) Mr. Waters gives his government students a quiz at midterm to determine whether he needs to spend more time on certain aspects of the federal judicial system.
C) Ms. Yarborough gives her introductory German students weekly quizzes to make sure they're keeping up with the material.
D) Mr. Zeller gives his science students a pretest before beginning a unit on the water cycle to determine how much they already know about the topic.