1) TAB: scrolls among answer choices from top to bottom.
2) SPACE BAR: "clicks" on the answer choice that you have selected with the tab key.
3) ALT-N: “Next (Question)” = Press these two keys simultaneously after you have selected an answer choice with the mouse.
4) ALT-Y: “Yes” = Confirms your answer once you have selected “Next”, and again saves time by avoiding another mouse click.
5) ALT-N : “No” = Choose this if you’ve changed your mind about your answer and want to re-try the question.
Mac users take note: for GMATPrep on a Mac, use the "Command" button instead of the "Alt" button. However, the real GMAT will always be on a PC which uses the ALT shortcuts, so this will obviously not work on test day.
Bonus shortcut for GMAT Prep - Review Mode only: Simply press the space bar to move on to the next question.