Final answer:
B.by fixing sentence fragments. The subject of this question is English, and the student needs help with fixing sentence fragments and subject-verb agreement errors.
Step-by-step explanation:
The subject of this question is English because it is asking about how to fix grammatical errors in sentences.
To address the errors in the given text, we can see that the student needs help with fixing sentence fragments. The sentences in the text are not complete and need to be revised to form complete thoughts. Additionally, there are some subject-verb agreement errors where the subject and verb do not match in number.
By addressing these errors in the text and providing examples of how to fix them, the student will learn how to write sentences that are grammatically correct.