The sentence communicates a matter of fact tone so the answer would be " matter of fact"
Answer:
same my answer and questions both are deleted
I would need to see the document to better understand the question. It is most likely one of these two-- See explanations below.
C. If the illustration something that uses descriptive words, it "illustrating" the process so that the student can better understand it. This could also be a diagram or chart
D. If the illustration is a drawing or photograph, the answer is most likely D because it adds color and holds the reader's interest. It uses imagery