Which of the following best describes "grandiloquence"?

The term "grandiloquence" refers to a lofty, extravagant, or pompous style of speaking or writing. It conveys a sense of using grand or elaborate language in order to impress or show off, often at the expense of clarity. This aligns perfectly with the choice that describes a high flown style, as it indicates an elaborate or florid manner of expression that is characteristic of grandiloquence. The other options, while they relate to aspects of communication, do not encapsulate the essence of grandiloquence; they emphasize simplicity or straightforwardness, which contrasts sharply with the notion of using a grand or theatrical form of speech.