Let \( x = (8\sqrt{3} + 13)^{13} \) and \( y = (7\sqrt{2} + 9)^{9} \). If \( [t] \) denotes the greatest integer \( \le t \), then:
\( [x] + [y] \) is even
\( [x] \) is even but \( [y] \) is odd
\( [x] \) and \( [y] \) are both odd
\( [x] \) is odd but \( [y] \) is even