Which of the following is not a valid MKAnnotationView property?

What does a '__block' type specifier mean?

Which is not a valid MPVolumeView method?

Which code samples will declare a variable inside a block in Objective-C?

What is true about Grand Central Dispatch(GCD) and NSOperation?

Which will print the value of a Boolean flag in NSLog?

Which are true regarding the usage of NSinteger and int in iOS?

What would be examples of troubleshooting steps to do, when Xcode displays a launching remote program error?

Which is a valid JSON string?

Which will create a singleton class that is compatible with ARC?

Which will get the position of UIView within the entire UIWindow?