Given an ArrayList of Strings, create and return a new ArrayList of Strings where each output String at index n is made up of all the characters with index n from the input Strings, in the same order they appeared in the input.

FYI

The data type of the output is List<String> just because CodingBat does not allow the creation of methods with a return type of ArrayList<String>. Because an ArrayList is-a List, you can safely pretend that the return type is ArrayList<String> instead of trying to create something called a List. The AP CSA curriculum used to require that students know what a List is (an interface), but no longer requires that knowledge.