Don't worry, panic is a normal state of being for many parents at this time of year. Just keep it away from the children because they need clear heads for this exam.
If it is any consolation, I have few state pupils who can do a decent Bond-style comprehension either but the smart ones can do multiple choice well enough. So, even if it is not multiple choice, your child is possibly no worse off than the vast majority of children sitting this exam. And, if it weren't multiple choice, it would have to be one word answers because the moment you get into sentence answers, the same person would have to mark all 4000 papers to ensure consistency, and I don't think you'd find anyone willing to trudge through 4000 comprehensions, no matter how much you were willing to pay them.
The watchword for this stage of the game is 'praise'. Praise them, then praise them some more. Shrug off any bad test results. Say something like 'I've heard from others that that is a really hard paper'. And whatever you do, listen to them if they say they are too tired to do work because it is usually true and they will write rubbish and then you will get anxious/annoyed, making them feel bad and defensive.
From many years of tutoring for this test, I have concluded that one of the key factors to success is how well the parents handle their children during the process.