Which of the Following Assignments Is the Best Example of "Free-Writing

Which of the following assignments is the best example of "free-writing"?

A) After studying a topic in life science, students are asked to write a summary of the main ideas and to develop examples.
B) After students are presented with an idea for a topic, they are asked to write whatever they want about it.
C) After students are given a chance to reflect on a recent event, they are asked to write a poem or short story about it.
D) After proposing a controversial topic for debate, students are asked to generate logical arguments supporting one side or the other.