You should be to get this from Quiz settings -> Results -> Statistics. That shows how many students got each possible question from the random selection. (Hmm, does anyone have time to edit https://docs.moodle.org/310/en/Quiz_statistics_report to add an explanation for how information about how random questions is shown?)

The other option is to use Quiz settings -> Results -> Responses. Turn on the option to also display question text. Then, probably, download that report, and analyse it in your spreadsheet software.

Or, if you don't mind going directly do the database (perhaps using https://learn2.open.ac.uk/report/customsql/) you could use some variant on this query: https://docs.moodle.org/dev/Overview_of_the_Moodle_question_engine#Detailed_data_about_an_attempt.