Yes "enhance" is correct according to this dictionary, and I think it is also correct in this context.
However it is best not to get too adventurous with the the thesaurus as Duo does not necessarily include all possible nuances of meaning of a word in its list of correct answers.
I got dinged for omitting the definite article. I think it should be accepted as well. We often speak of quality as such, especially if the context is already a given. Imagine a discussion in a board meeting or a press conference and everybody knows what we're talking about, it seems to me somebody can quite validly say "we're improving quality."
Honestly.. I am ready to quit. It was a good run but all I do now is just try and guess what duo is thinking.
"We are making the quality better"....it's the same thing..And please don't be that douche who says 'Omg totally different that would be 'facciamo la qualita migliore''...
Yes I know "just check 'My Answer should be accepted!!1!!'", but its too much.
Thank you Duo. It was Great and I learned a lot! I will recommend it to beginners who are interested in learning a new language.
Hopefully I will start again soon.