单选题：A "full tree" of degree 3 (every non-leaf node has 3 children) h

A "full tree" of degree 3 (every non-leaf node has 3 children) has 31 nodes. Then its height $$h$$ is at most ____. Note: $$h=0$$ for a single node tree.



A.cannot be determined
B.11
C.10
D.9


答案：C