C. With plagiarism increasing, teachers and schools are making the appropriate decision to fail or expel students who are caught plagiarizing.
Explanation:
The arguments shown in the question give due support for what is being discussed in letter C. Both the arguments and the letter C speak about the concern of teachers and schools about the increase in plagiarism, the idea that some students have that will not be taken when they do plagiarism and the consequences that plagiarism will cause to these students.
