在页式存储管理方案中，若采用二级页表，取一个数据或指令至少要访问（）次内存。

A．SELECT S# FROM SC GROUP BY S# WHERE COUNT(*)＞3
B．SELECT S# FROM SC GROUP BY S# HAVING COUNT(*)＞3
C．SELECT S# FROM SC ORDER BY S# WHERE COUNT(*)＞3
D．SELECT S# FROM SC ORDER BY S# HAVING COUNT(*)＞3