Which One of the Following Is the Best Example of Dynamic

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

A) Mr.Thiessen asks Macy to show him how to use a microscope properly.
B) Ms.Ursinas asks her students to work in groups of three to write a paper describing the effects of the U.S.invasion of Iraq in 2003.
C) Ms.Vincenti gives her students 20 multiple-choice questions; she then gives 20 additional, more difficult questions to students who've done very well on the first set, as a way of assessing the upper limits of their knowledge.
D) Mr.Warren observes and records how Erica's logical thinking changes over time as she experiments with a pendulum and how she responds to his hints about separating and controlling variables.