单选题：A red-black tree with N internal nodes has height at most_______

A red-black tree with N internal nodes has height at most______________. @[A](3)

A. 2ln(N +1)
B. 2ln(N)+1
C. ln(2N +1)
D. ln(2N )+1



A.2ln(N +1)
B.2ln(N)+1
C.ln(2N +1)
D.ln(2N )+1


答案：A