Another hypothetical question. You need to consider the most marketable aspects of the "product" and concentrate on these. What marketing method would you use? Whose help would you seek? And what research into past marketing attempts could be helpful?

Be prepared to discuss the product in terms of making it profitable. Concentrate on the positive and declare who you would try and sell GB plc to. You could even consider whether it needs marketing. Perhaps it could sell itself with just a little help from you.