The sum of the numerical coefficients in the complete expansion of (x^2 \minus{} 2xy \plus{} y^2)^7 is:
<spanclass=′latex−bold′>(A)</span>0<spanclass=′latex−bold′>(B)</span>7<spanclass=′latex−bold′>(C)</span>14<spanclass=′latex−bold′>(D)</span>128<spanclass=′latex−bold′>(E)</span>1282