单选题：A B+ tree of order 3 with 21 numbers has at most ___ nodes of de

A B+ tree of order 3 with 21 numbers has at most ___ nodes of degree 3. @[D](3)

A. 1
B. 2
C. 3
D. 4



A.1
B.2
C.3
D.4


答案：D