I looked at the question and was off to figure it out. I actually ended up running the query as it was written and got 20 results which showed six unique values. I doulbe checked this by running this
select Top 20
RAND(RANK() OVER ( ORDER BY id )) as fred
FROM sys.syscolumns AS s
This gave me 6 numbers. But I know that QotD's are tricky so I looked at the total results and saw of the 20 returned values in detail there was only one that was truly unique. All other were repeated at least once. Understanding the definition of Rand to me the answer was that there were 20 results but only one was random, or at least not repeating. I then looked at the question where possible answers were given and found 1 was not an option.
Reading further there was the explaination of the question and that it was problematic. So I took the answer of 2 just to read the discussion to see if others got where I did.
Not all gray hairs are Dinosaurs!