This practice, which Marcus conducted is known as Plagiarism.
Answer: B
Explanation
Plagiarism is an unacceptable practice of copying someone's ideas and publishing them as one's own.
There are many definitions given by Literature scholars on this aspect.
Some scholars see it as stealing an idea or a literary theft while others see it as being ungrateful for not accepting the original source from which the ideas are taken.
According to US law, ideas expressed by an individual are his intellectual property and comply with copyright laws, the same seen with inventions.