There should be a way to practice previously missed questions without the correct answer being highlighted

SUGGESTION FOR KHAN ACADEMY'S SAT PREP

As stated in the title, there should be a way to practice previously missed questions without the correct answer being highlighted. This would help a lot with learning from mistakes.

Let's say you want to review a question you missed a month ago. The problem with the system now is that it will automatically highlight the correct answer for a question that you missed, so it is almost impossible to retry a missed question from scratch. 

What I suggest is that the default setting for missed questions is to not highlight what the correct answer choice is. If the user still is stumped, then perhaps Khan academy could implement a switch to hide/show the correct answer choice and the incorrect choice the user selected previously.