Answer: b. Paraphrasing plagiarism
Explanation: paraphrasing plagiarism is when you have used someone paper work or idea, without acknowledging the person, and pretending to be the original owner of that work, as you have tried to rephrase the words to your own words,
The student version has copied the original version, without acknowledging the original version, the student just tried to change the words, using his own words, even though he has copied some key points, words to words.
It is called paraphrasing plagiarism, also because the student has added nothing new to his write-up, making his write-up, look more like the original source.