Our company's training program has multiple choice and true or false answers for our retention testing. You can't answer multiple choice with a yes or a no. You could probably answer yes for true and no for false but that is not ideal. Instead of a dropdown box with yes or no, it would be much more versatile to have a customizable answer, therefore you could answer yes or no, true or false, multiple choices or anything else you would like for an answer. It doesn't seem to me like it would be a large project to accomodate this idea. Realistically all you would have to do is take the yes or no drop down out and put in a blank box.
Major updates to the Training Module are planned for the future.