1 C because insert isn't a valid function 2 B because check isn't a valid function 3 A because binarySort isn't a thing (it's binary search) 4 B because find isn't a valid function And just to let you know, I never knew any of these existed, but what I did is I searched up "java array functions," and skimmed through the documentation for the functions online. If you are a Computer Science/ Software Engineering major, this is something you should know how to do. If you want the website: docs.oracle.com/javase/7/docs/API/java/util/Arrays.html