Plagiarism is often times described as letter D: Both b & c - literary theft and cheating. Because in plagiarism, you copy the either word by word and the thought of the article without referencing the original author and publish it as your own. In this essence, you are not respecting the author of the article and his intellectual expression. This is not an honest mistake because an honest mistake is something not done on purpose while plagiarism is done on purpose.