一、单选题
1、When solving a problem with input size N by divide and conquer, if at each stage the problem is divided into 8 sub-problems of equal size N/3, and the conquer step takes O(N2logN) to form the solution from the sub-solutions, then the overall time complexity is __.
A.O(N2logN) B.O(N2log2N) C.O(N3logN) D.O(Nlog8/log3)
解析：A。由于我们有主定理：
对于在满足有
，
，
时有解为：
$$ T(N)=\left\{
