So 36% of people thought that either: You don't need to compare them since the graphical plans are the same, which is blatantly false, or that You can compare the tool tips to arrive at the differences, which is also completely false since the differences are on property values not found in the tool tips. I'm sorry if anyone thought those were correct answers, they're not.
As to checking the property values one by one, which 24% thought it was... sure, I suppose that can be construed as a possibly correct answer. Please feel free to check all the properties on the attached picture of a plan to identify any differences if I supply a very similar or nearly identical plan... I'll wait... In short, a possible answer, but certainly not the best possible answer.
I didn't include the version of SQL Server because the new functionality covers 2012, 2014 and 2016. SSMS is divorced from the SQL Server engine now (and you should absolutely not be running the GUI directly on your production servers, regardless of the version).
It's one point out of 10 million possible points. Personally, I'd let it go.