I guess this could be implemented fairly easy. However I would consider it bad practice to study material using multiple-choice.
Here is why:
Multiple-choice already provides you with the answer. You just have to passively choose it. The learning and the consolidation of the knowledge will be much more effective if you have to actively recall it.
For your example you could simply ask “Which is the most important organ?” Or, if you want to remember all of them, make it a list: “Name the four most important organs”. This sounds like it is more work, but you have to type it anyway for making a multiple choice card. And thinking about your content while creating cards goes a long way towards remembering it.
Additionally, multiple-choice creates a rigid framework, which is hard to escape. Meaning it is not likely you will be able to use the knowledge again, beyond this specific question. Let alone know the answer if no choices are given.
Even if you are studying for a multiple-choice test you are probably better off not using multiple-choice as a learning method. What if they mix up the questions, and your answers do not fit anymore? Often, the same information gets quizzed in multiple questions. So instead of copying three multiple choice cards, you could just create one active question.
I had to do multiple-choice on several occasions and (after failing once) never used it as a format for my flashcards again. Which I do not regret.
Of course I neither can nor want to force you to stop using multiple-choice. If you have good reasons to do so, feel free to ignore my post (or even better, share them).
For the feature you are proposing I suggest making the answers shuffle every time they get shown in the queue. So the first time you review it A) might be Brain, the second time it might be Liver. This prevents recognising the answer by its position.