用坩锅钳夹住一小块刚用酸充分处理过的铝箔，在酒精灯上加热至熔化，发现熔化的铝并不滴落．下列关于上述实验现象的解释正确的是（　　）

A．火焰温度太低不能使铝燃烧

B．铝在空气种能很快形成氧化膜

C．氧化铝的熔点比铝的熔点高

D．用酸处理时未能将氧化铝溶解

Are based on the following Pascal code.FOR i:=1 TO n -1 do BEGIN k:=i: FOR j:=i+1 TO n DO IF A[j] THEN k:=j: IF k<>i THEN BEGINX:=A[k]; A[k]:=A[i]; A[i]:=x END END;<---> Suppose elements in array A are already sorted ascending order of their values when the code begins to run, then execution time of the code will be

A． O(log2n)

B． O(n)

C． O(nlog2n)

D． O(n2)