Alternatively put, 60% didn't give a hoot, so by opting out they chose to go with the majority view, which was 60% in favour.
It rather reminds me of people who say that they never bother to vote and then complain bitterly, and at tedious length, about the shortcomings of their local council or the government.
It also sounds like George Bush: "If you're not with us, you're against us."
Parents sometimes don't respond because consultation documents confuse them, and it is those least able to access what they perceive as the best educational opportunities for their child who lose out...always.
Another view is that the 10.8% who voted for scheme B are regular contributors to this forum.
However, in terms of statistical surveys the 10.8% still remains, since raw statistics cannot make presumptions.