Hi Zach,
I just verified that the correct answer given is indeed A A A (Option 4) (and not A B A). There haven't been any updates to this question either so it has been like that for quite a while.
A detailed explanation is also provided with this option:
There are two things here:
1. When you don't specify the argument index or relative indexing (i.e. the < flag) in the format specifier, it means that you are using ordinary indexing. Each format specifier that uses ordinary indexing is assigned a sequential implicit index into argument list which is independent of the indices used by explicit or relative indexing.
The ordinary index starts with the first format specifier that does not use explicit index.
In this case, it starts with the middle %s. Therefore, it prints the first argument which is A.
2. < is used for relative indexing. It means you want to use the argument that was used for the previous format specifier. In this case, it was A. Therefore, it prints A again.
This is explained further here: http://docs.oracle.com/javase/7/docs/api/java/util/Formatter.html
BTW, if you find any issue/error with any question, you may just click on the Discuss button on the bottom on the question view, and it will take you to any existing discussion about that question. If there is no existing discussion, you may start a new one.
HTH,
Paul.