The correct answer is A. frustrated.
The word “forlorn” means “sad and lonely,” while the word “wretched” means “very unhappy or unfortunate.” Both of these words suggest that the friend is feeling a great deal of sadness and unhappiness. However, the word “frustrated” also suggests that the friend is feeling a sense of helplessness or powerlessness. This is likely because the friend is unable to change the fact that his mother has died, and he may be feeling angry or resentful about this.
The other options are incorrect because they do not accurately describe the friend’s feelings. The word “lonely” does not capture the sense of sadness and unhappiness that the friend is feeling. The word “fearful” does not accurately describe the friend’s feelings because there is no indication that he is afraid. The word “gloomy” does not accurately describe the friend’s feelings because it does not capture the sense of sadness and unhappiness that he is feeling.