Which of the following is an example of reflexive writing?

research paper

essay

letter to the editor of a newspaper

diary entry

I think you mean reflective.

Reflective writing is an analytical practice in which the writer describes a real or imaginary scene, event, interaction, passing thought, memory, form, adding a personal reflection on the meaning of the item or incident, thought, feeling, emotion, or situation in his or her life.

Therefore, the answer would be a diary entry, because it is a personal piece of writing.