The CAA exams are really a joke. What is said by you is correct. Many times you get an answer, where you know for sure its the right one, but according to Exam answers its incorrect.
And also true, is the bad English. Especially now in changing questionbank, its really frustrating, that you see a lot of questions in CAA exam which you have never seen before. It is not that you dont have the knowledge, but just not understanding the question. Because how they build up a sentence it totally doesnt make any sense what they try to ask. So how should you ever find the correct answer?