This question had been raised three years ago. In 2023, there does not seem to be an option to remove the 'Confidence' prompt.
I find it to be a distraction while I practice. After I selection an option, I often want to double-check the answers, but the 'Confidence' prompt pops up, which blocks some of the answers, and I have to click it away. This could take away seconds of concentration from each question, and impede practice the more a person delves into their timing on responses, etc.