francisco de feudis wrote:Shouldn't it be B, C, E? Are not A and B mutually exclusive ?
That seems to be an English thing. So it is not a typo. We had a fairly lengthy discussion on the topic though. Here is another topic about this question (with exactly the same conclusion).
francisco de feudis wrote:Is the interface inherited? Isn't it implemented?
When a concrete class implements an interface, the concrete class must implement all methods from the interface. But in this question it is about superclasses and subclasses. When a subclass doesn't implement any interface, but the superclass implements an interface, the subclass indirectly implements this interface through inheritance. So this interface could be considered as an inherited interface (from the subclass' point of view), thus it is not an errata item.