Thanks to all who have the courage to answer this question before tomorrow.
At this moment the incorrect answers are still the majority.
And they are still the majority.
It's a nice simple straightforward question, seems odd that it's worth two points (as it's something every DBA or Database Developer should know off the top of their head), but as the majority of answers so far are wrong maybe two is fair enough. Anyway, the proportion of wrong answers still being above 50% made me look at the BOL page to see if there's anything there that could lead people astray; as far as I can see there isn't, but the information they need would to discover the answer to the question is missing.
I wonder if people are getting it wrong because they look it up (as I do with, for example, pivot). The shiny new BOL page (referenced in the explanation) has quietly omitted the BNF for <column definition> - BOL dropping information again. The feature list may improve from release to release, but it's becoming a solid tradition that BOL gets less complete and more difficult to use from release to release, and this indicates that 2016 is continuing that unfortunate tradition.