[LON-CAPA-users] Hints for first LON-CAPA question

[Joseph Mingrone]

Gerd, Raymond and Peter;

Thank you all for your helpful suggestions.  I'm starting to
get a better sense how everything fits together.

I have a (hopefully simple) followup question.  For a Radio Response
problem with randomization, is there a simple way to group the randomly
chosen questions?  Say there are 5 possible answers

1, (2a, 2b), (3a, 3b), (4a, 4b), (5a, 5b).

Is it possible to randomly select only one version of an incorrect
answer?  So possible options shown to the student might be 2a, 1., 3b or
5b, 4a, 1, but not 2a, 2b, 1.

I guessed putting the answer versions in a foil group together might
give the functionality, but it didn't seem to work.

Thanks,

Joseph