I know the instance variable in ARC are by default `__strong`. How can I release an instance variable when the containing class is still retained. In the following example `v` is `__strong` 

and `c` is allocated when object of A is created some where and retained. I want to release the
`c` instance variable. How to should I do that?, What should be in `releaseC` method that will release the `c` instance variable. 

```
@interface A {
  Obj *c;
}

@implementation A {

 - (id)init {
   if((self = [super init])){
     c = [[Obj alloc] init];
   }
   return self;
 }

 - (void)releaseC {
  //what should be here?
 }

}

```