I am creating an eBook that has multiple choice questions with the answer greyed out. I would like to find a way to cover the answer box with a color graphic box and be able to click on it and move to the background. Is this possible? Other options?

I have created an eBook using iBook Author. It contains multiple choice questions with the answer in a separate cell in the lower left of two rows and is grey in color so users do NOT simply look and see it. I would rather like to find a way to create a graphics box over the answer and have a user click on the box to then make the blue box move to the background displaying the answer A, B, C, or D. Is there any way to do this?

As an alternative, is there a way of using a WIDGET, which I am unfamiliar with, to accomplish this task. I just don't want the ANSWER to the questions (1030 of them) to be readily visible and would like the user to select to display the answer after they have selected their desired answer to see if they got it correct. If this display and undisplay could toggle on or off (to show or hide) the answer that would be great.

Thanks in advance for any recommendations.

Richard