I don't think they'll tell you because I emailed them just before the end of the application deadline asking them the same thing and they said they can't tell me. I'd suggest you ask your head of year or who ever sent your predicted grades because they will be more likely to tell you.
Does that mean that you got an offer based in your yr 10 grades?
No, I found out about the problem before HBS sent the reference request so I asked all my teachers to give me my current predicted grades and told my head of year to send those off, not the ones based on my primary school results.