Answer honestly! The actual example you choose is immaterial. They will be looking for enthusiasm and a real interest in the subject you choose - obviously pick a story that you know something about as you may get questioned about it.

A similar question is about who you would like to interview and what would you ask them.

Try and demonstrate in your answer:

* Your awareness of a big news story

* The need for accuracy in its reporting

* Elements which made it noteworthy

* What extra you might have brought to it

* Questions you would have asked

* An angle you might have taken