I would only ever say ‘The man who arrived yesterday needs a wakeup call at nine’; but this option wasn’t available. For want of a ‘none of the above’ button, I clicked ‘The man that arrived’ as being the only one I have ever heard anyone using.
The quiz also asks whether a number of sentences ‘are grammatical’, including:
1. I’ll write my brother.
2. I’m just after telling you.
3. She resigned Thursday.
4. I’m wanting dessert.
5. Who did Sue ask why Sam was waiting?
6. Who did Bill ask why Jane was talking to?
That confused me because while I would not myself use the constructions in 1-4 because these are not natural to my dialect, I certainly wouldn’t say they ‘weren’t grammatical’. Conversely, while I do not consider 5-6 grammatical I actually would use them in speech, though not in writing. The instructions simply didn’t make clear whether I should have clicked in these cases.
So, although the algorithm correctly identified me as a UK speaker, I don’t know how useful my response was.