i went into the student portal (the U.S. one) to check the answer keys to the exam we took...and found myself laughing instead at what the teacher did...she did say she was going to post the answers so that we could do self-scoring...or guess what we may get...here was what greeted me earlier (not the exact thing but similar):

exam one:
b
c
d
a
b
c
d
...
exam two:
c
d
e
a
b
c
...
exam three:
a
b
c
d
d
e
...

so there are three versions and three answer keys...err..who in the right mind would have remembered the a or b or c or d for a particular question...if she did this to humor us..well she definitely did a good job.