This is a predicate adjective, as it immediately follows a copulative (=linking) verb "to grow". If it said - The tall grass, then "tall" would be nominative. This way it isn't, it is a predicative adjective.
As an English speaker the advice i give to someone who wants to learn English would be it does take time but it's actually not that hard to learn English you just need to keep practicing and try to talk with the words you know so you can get used to it.
Answer:
A- skillfully
I very sure but I think I'm right
