Which is equivalent to (4 x y minus 3 z) squared, and what type of special product is it?

16 x squared y squared + 9 z squared, the difference of squares
16 x squared y squared + 9 z squared, a perfect square trinomial
16 x squared y squared minus 24 x y z + 9 z squared, the difference of squares
16 x squared y squared minus 24 x y z + 9 z squared, a perfect square trinomial

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