A subsidiary company has a 80% controlling interest was acquired in when it had equity shares with a book value of £800,000 in issue and retained earnings of £600,000. The book value of the subsidiary’s equity shares remain unchanged but retained earnings are now worth £900,000. What value should be attributed to the non-controlling interest in this subsidiary?

A £60,000

B £180,000

C £280,000

D £340,000