What does the term ostentatious refer to?

The term "ostentatious" refers to something that is characterized by vulgar or pretentious display, designed to impress or attract notice. It often implies an excessive showiness that can be tawdry, indicating that the display is not only exaggerated but may also lack taste or elegance.

In the context of the other choices, "something that is simple and understated," "a practical design choice," and "something that is innovative and modern" do not capture the essence of ostentation. These alternatives suggest a level of subtlety, practicality, or modernity that contrasts sharply with the connotations of excess and vulgarity associated with ostentatious displays. Therefore, the choice that conveys the sense of flashy and extravagant appearance aligns best with the definition of ostentatious.