If you force me to guess, then I'm going to guess. Not only does that give me a 25% chance of getting it right at random, but as others have pointed out, it is very hard to make a multiple choice question that isn't guessable by an astute enough test taker. I think I knew 80 - 85 of those words, but I scored 97, because those questions were very guessable.

Also, reiterating everyone else's comments with respect to the UX needing fewer clicks, and also the definitions not being exact or precise in many cases.

But then below it said "you are a man of few words".

I take it the latter is just because I've only done the test once? But it's mixed messaging on first attempt I think.

There were many words I couldn't have explain the meaning of at all, if I wouldn't have had the options, but having the options made it easy. I wouldn't count those correct answers as a part of my vocabulary (even passive), even if I could answer with relative confidence.

So it's not uncommon to see a native English speaker totaling 90 as 20,20,19,17,14, and a foreigner reaching the same total as 18,18,18,18,18. Strangely enough, the algorithm favors the latter, because it assigns more weight to the higher-end bands.

Is this of any use? I doubt so, but it was fun.

P.S. of course a more reliable clue of nativeness is the use of "its" and "it's" interchangeably, a mistake EFL learners wouldn't do.