对于具有n个元素的关键字序列{k1,k2,...,kn},当且仅当满足关系ki>=k2i且ki>=k2i+1(i=1,2,...,[n/2])时称为大根堆。据此可以断定,( )不是大根堆。A.59,53,48,46,37,31,25 B.59,46,53,48,37,31,25 C.59,37,53,25,31,46,48 D.59,53,48,31,25,46,37