单选题

下面的代码段,第一个str的retainCount是多少？第二个和第三个呢？ =

Question

下面的代码段,第一个str的retainCount是多少？第二个和第三个呢？
=======================================================
NSMutableArray* ary = [[NSMutableArray array] retain]
NSString *str = [NSString stringWithFormat:@"test"]
[strretain]
[aryaddObject:str]
NSLog(@"%@%d",str,[str retainCount])
[strretain]
[strrelease]
[strrelease]
NSLog(@"%@%d",str,[str retainCount])
[aryremoveAllObjects]
NSLog(@"%@%d",str,[str retainCount])
=======================================================

A. 321

B. 210

C. 432

D. 320