If a student knowingly borrows an author's words without giving the author credit,

that student is guilty of

intentional citation

unintentional plagiarism

unintentional reference

intentional plagiarism

Intentional plagiarism because the student is aware that they are using someone else's words and not giving credit

The correct answer is "A. intentional plagiarism". Plagiarizing is copying from someone else without being given the permission, or giving the author credit. If you do however give him credit everything will be legitimate and it will be considered to be a citation.