A binary tree of depth “d” is an almost complete binary tree if .
选项：

A:(i) Each leaf in the tree is either at level “d” or at level “d–1”;
B:(ii) For any node “n” in the tree with a right descendent at level “d” all the left descendents of “n” that are leaves, are also at level “d”;
C:Both (i) & (ii);
D:None of them