What prints to the console?

Senior PRO

Task

Objective-C, the project is built without ARC (MRC), the code runs on the main thread:

NSObject *object = [NSObject new];
dispatch_async(dispatch_get_main_queue(), ^{
    NSLog(@"A %lu", (unsigned long)[object retainCount]);
    dispatch_async(dispatch_get_main_queue(), ^{
        NSLog(@"B %lu", (unsigned long)[object retainCount]);
    });
    NSLog(@"C %lu", (unsigned long)[object retainCount]);
});
NSLog(@"D %lu", (unsigned long)[object retainCount]);

What prints, and in which order?