How does Twain's use of a rhetorical question in this excerpt advance his viewpoint?

Here were no scenes but summer scenes, and no disposition inspired by them but to lie at full length on the mail sacks in the grateful breeze and dreamily smoke the pipe of peace--what other, where all was repose and contentment?

It indicates that Twain is questioning his choice of transportation.

It highlights Twain's concern with this method of transportation.

It emphasizes the fact that Twain is unsure of his thoughts on traveling by stagecoach.

It reveals Twain's belief that there is no better way to travel than by stagecoach.