A nice question, but the answer is not completely accurate.
If you read the explanation in page that is linked to, you'll see that the actual name of the endpoint depends on whether or not the report server is configured for SharePoint integrated mode. If it is, the endpoint uses 2006 in its name, without SharePoint integrated mode, it uses 2005. And since the question did not mention SharePoint integrated mode, I now foresee a whole lot of replies from people demanding their points back (even though, for anyone who doesn't just pick an answer at random, it should have been perfectly obvious what the intended answer is!)
Oh, and there is indeed also a "not" missing in option 3. Again, obvious from context. And, again, probably a reason for a lot of whining about wanting points back (as if everyone's pay check depends on the points earned here...)
Hugo Kornelis, SQL Server/Data Platform MVP (2006-2016)
Visit my SQL Server blog: http://sqlblog.com/blogs/hugo_kornelis