What term describes the author's argument that he/she intends to prove?

The term that best describes the author's argument that he or she intends to prove is "thesis." A thesis statement is a concise summary of the main point or claim that the author is asserting in their work. It serves as a roadmap for the entire argument, guiding readers on what to expect in the ensuing discussion and helping to clarify the author's position.

While claims might refer to specific assertions within the text that support the overall argument, the thesis encapsulates the primary argument in a clear statement. The conclusion typically refers to the final thoughts or summing up of arguments presented, and a hypothesis is often used in scientific or experimental contexts to suggest a testable statement rather than to summarize an argument. Thus, the thesis is the most accurate term for the primary argument the author seeks to prove.