Sorry Sue, I didn't reply to this earlier. We currently have four challenge questions one of which is selected at random.
The Q&A regime was put into place a number of years ago to circumvent mass, (and I mean hundreds) of daily automated registrations that we had to tidy up with the previous regime that the board originally defaulted to. It was so bad at one time that I had to suspend all registrations to get on top of the problem.
This method works but as always I am open to suggestions as long as it doesn't open the floodgates again. We can define more in the selection list, if you want to make any suggestions please feel free. Please use the PM function on the site for any suggestions.