Page length.

I would have thought that would be a minimum. This is a 4 hour exam, so even allowing time for reading and planning this is around only 3 pages per hour and I wonder if the answers are as full and as detailed as expected. Of course, a lot depends on what you have written rather than the amount and certainly don't try to write more for the sake of it.

Do you mean that 11 pages is minimum?

Yes