The issue with discovering a perfect solution to a problem is that

The issue with discovering a perfect solution to a problem is that We cannot predict the consequences perfectly before the perfect solution

While finding the perfect solution we consume a lot of time and the perfections comes when the experiment is repeatedly performed again and again. A tiny mistake can lead us to a very different result therefore it is not sure that the solution that we are finding is a proper and perfect solution.

answer; (a) brake pedal is depressed;