Answer:
A. to comment about an issue facing society is the correct answer.
Step-by-step explanation:
In literature, a theme is defined as the main idea or the meaning behind the work. Theme can be literally mentioned or just inferred by readers. It is different from the subject, which is the topic of the work.
Letter B is incorrect because the one who explores creativity is the author at the moment of writing.
Letter C is also incorrect because not all themes are related to the author's life.
D is also incorrect because elements of surprise and mystery are not the only that could be introduced by choosing a particular theme.
This way, letter A is correct; based on the definition, any theme can be chosen as long as the subject is helpful to do so.