Furigana under point says か but below says が. Is there a mistake somewhere here?
I’ve just reached this point in N2 as well and, given some of the other vocabulary I’ve encountered, I wouldn’t be surprised if some stuff mid-word is pronounced differently simply because of minor variations that naturally occur in a language.
As an example, 行き would almost always be いき, but recently in phrases like ロンドン行き both ゆき and いき become perfectly acceptable.
I’d venture to guess by itself it would be か but because it’s connected to another word it becomes が.
Looks like it should be がけ here on the grammar point furigana. Thanks for pointing out the error to us! I have just fixed it and apologize for the inconvenience!