The first choice "Who makes more than you" is another of Dulingo's stupid tricks, put in purely to annoy. Stop it. "Who makes more than you" is a perfectly correct translation into UK English and if included as a choice should be accepted as correct.
But is it perfect in binary? I challenge you to try and do better. Think of the programmers! I bet you don't even know how hard it is to teach a language using a different language, in this case Java.
It's for comparisons of inequality, i.e, one thing is more or less than another. This explains it in more depth. http://www.uvm.edu/~cmazzoni/3grammatica/grammatica/comparatives.html
Nei casi in cui un pronome come "who" (o what, which, whose) è il
soggetto della frase, la domanda non ha bisogno di "to do" e ha lo stesso ordine delle parole come la frase indicativa.
Subject questions are questions that we ask to find out about the
subject. When "who" (or what, which, whose) refers to the
subject, the question word comes before the verb without the use of the auxiliary verb.
waslate? => The train to London was late.
wonthe race? => I won the race.
gaveyou those chocolates?
- Which film
Source (with modifications)
Si potrebbe dire "who does earn more than you," ma non credo che sia una interpretazione giusta in questo caso. È coretto dire "who earns."
I guess you're talking about the exercise called tap the pairs? You're supposed to click on two words that mean the same thing, for instance 'gatto' and 'cat', until you've used all the words.
Does "guadagnare" also mean "to gain"? That would make "Who gains more than you?" an acceptable choice. I was watching a detective show on TV, and that was what was said! Coincidence?