Which of the following is most responsible for making Life on the Mississippi a great example of American Realist writing?

A. Twain's unbiased descriptions

B. Twain's use of idioms

C. Twain's imaginative characters

D. Twain's objective commentary

A. Twain's unbiased descriptions

Mark Twain's "Life on the Mississippi" is often cited as a notable work of American Realism for its detailed, faithful portrayal of life along the Mississippi River. Twain's firsthand experiences as a steamboat pilot allowed him to give unbiased and meticulous descriptions of the setting, culture, and the people who lived and worked along the river. This adherence to realistic depiction of everyday life is a hallmark of the Realist movement in literature, which sought to present subject matter truthfully without artificiality or implausible, exotic elements.