Final answer:
The correction for the subject-verb agreement error in the given sentence is to use 'is' instead of 'are' to match the singular subject 'a student.'
Explanation:
The correct sentence that fixes the subject-verb agreement error is:
- A student who submits a research paper with a weak thesis and multiple sources is going to receive a higher grade than students who submit a research paper with a strong thesis and only a few sources.
When the subject consists of two or more nouns connected by 'and,' the verb should be plural. In this case, 'a student' is the subject, which is singular, so the verb 'is' should be used instead of 'are' to ensure proper agreement.
Learn more about Subject-Verb Agreement here:
https://brainly.com/question/29783458