The challenge asks to “find the method” for a case-insensitive search.
I looked in the docs, and found that rangeOfString: “Invokes rangeOfString:options: with no options.”
If you look at rangeOfString:options:, one of the options is NSCaseInsensitiveSearch (this is not a method, right?).
Is there a method to use instead, or should the challenge have asked for an option (instead of a method), or is this option somehow also a method?