Question presentation/random positions/visual task

A kind hi to everyone again,

I am trying to figure out how to present at random intervals a specific question. I have an experiment with image presentation and at a random interval of about 10 trials with plus/minus 3 I want a question to appear asking The Next image will be a X or Y?. Up to now I have created the question in this loop with adding a clock in the beggining of the experiment and this code:

interval = random()*(13-7)+7
if startClock.getTime()-lastCheckTime > interval and not showTaskB:
showTaskB = 1
lastCheckTime = startClock.getTime()

When the question is shown then there is another code:

Show Task b = 0

So everyhting ok up to now. I want in its questions based on the next image to have a correct and a random option? So if the next image will be Z, the question should be Next image will be a Z or a Y?
I would like to create a vector with the random positions of the questions and then recognize the next trial to create a variable in the text component for each of them. And the position should be different across participants. Any idea how can I achieve that?
Thank you so much in advance and sorry for all my posts the pasts days.