Answer:
D He starts to spell badly again.
Explanation:
Daniel Keyes's science-fictional story "Flowers for Algernon," tells the story of Charlie Gordon, a mentally disabled man. The plot follows him from his mental disability to becoming intelligent to such an extent that he encompassed his peers but then reverted back to his old self, rendering him the same developmentally disabled man once again.
At the beginning of the text, we see Charlie as a mentally unstable and disabled man, prepped for a scientific experiment to help him become more intelligent. Then, after he became intelligent, he would do things better than the others. Throughout the "diary entry" of Charlie, we can see his development based on his writing skills.
First, he couldn't spell properly, then became better and excelled in it. He then again began to spell incorrectly, which is a sign of his deteriorating condition.
Thus, the correct answer is option D.