Asish,
Welcome to CodeRanch!
There was a lot of debate about that question.
The intent was that allowed means "can be, but doesn't have to" and required means "must be". We considered allowed to be a subset of required. So if something is required to be handled, it is also allowed to be handled. That said, we agree this is confusing and have change the question for our
Java 11 cert book. While the exam does have some
word problems, they aren't on the definition of the word "allowed"
Also, the real exam tells you how many answers are right. If this said "choose 4", you'd have gotten it right. You'd get B, C and E right away. Then you'd puzzle on the others and conclude that A is "more right" than D/F which are clearly wrong!