The answer is D. Thesis.
A magazine is a periodical publication that typically contains articles, stories, and other features of general interest. A novel is a long fictional narrative, typically published as a book. A dictionary is a book or electronic resource that lists the words of a language (typically in alphabetical order) and gives their meaning, or gives the equivalent words in a different language, often also providing information about pronunciation, origin, and usage. A thesis is a long essay or dissertation that is written by a student as part of the requirements for a degree.
Thesis is different from the rest because it is the only option that is not a type of publication. A magazine, novel, and dictionary are all types of publications, while a thesis is a piece of academic writing.