A.
won't terminate for any value of n. 对于所有的n都是无穷的
B.
won't terminate for some values of n (but will terminate otherwise). 对于部分n是无穷的
C.
We don't know if it termiates for any value of n. 不能确定是否存在n,使程序无法终止
D.
always terminate for any value of n. 对于所有的n都是有穷的