Why does the main character pay the bigwigs?

Which sentence corrects the error in subject-verb agreement? 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. a student who submits a research paper with a weak thesis and multiple sources is going to receive a higher grade than students who submits a research paper with a strong thesis and only a few sources. a student who submit a research paper with a weak thesis and multiple sources are going to receive a higher grade than students who submit a research paper with a strong thesis and only a few sources. a student who submits a research paper with a weak thesis and multiple sources are going to receive a higher gesubmits a research paper with a strong thesis and only a few sources

It was a bitter cold saturday morning ,the young track star dressed for his daily five mile run

Which number is main idea? i need this quick.