计算(x的四次方+y的四次方)(x的二次方+y的二次方)(x+y)(x-y)的结果

=(x－y)(x＋y)(x²＋y²)(x的4次方＋y的4次方)
=(x²－y²)(x²＋y²)(x的4次方＋y的4次方)
=(x的4次方－y的4次方)(x的4次方＋y的4次方)
=x的8次方－y的8次方

选【A】