某对分查找算法的VB程序段如下: i= 1:j = 9:n =0 key=Val(Text1.Text) Do While i<= j n=n+1 m=Fix((i +j)/2) If key = d(m)Then Exit Do If key<d(m)Then j= m -1 Else i=m+1 Loop 数组元素d(1)到d(9)的值依次为“7,12,18,25,39,58,61,72,86”。若该程序段运行结束后,n的值为2,则key的值是( )
A . 39
B . 18或61
C . 18或72
D . 12或61
答案:D