Answer:
C). Thesis.
Step-by-step explanation:
The thesis is demonstrated as a statement that proposes the central claim, argument, or idea of an essay or speech which is going to be discussed. This aids to inform the reader about the topic and key argument of the work and prepares them for the essay or speech. The rest of the essay or speech is developed around backing and substantiating the arguments presented in the thesis and turn the argument into a belief for the readers. Thus, the specific detailed subject for an essay or speech would be 'thesis' as it offers clear and concise information regarding the key argument of the author. Therefore, option C is the correct answer.