An old one but a good one

Thanks to Peet Morris for reminding me of this little puzzle for the weekend.

Multiple choice:
If you choose an answer to this question at random, what is the chance you will be correct?:

A) 25%
B) 50%
C) 60%
D) 25%

I'm not going to suggest a 'right' answer (though there are at least two) - I leave it up to you.