The best thing to do is here is check the explanation. If the explanation does not suffice, or suggests the wrong answer, you will be prompted on why you think you got that question wrong. One of the options is 'The question or answer(s) is incorrect'. If you click this, we will get notified and make sure the question gets the treatment it deserves. If the question does not make sense, you can click on 'Don't know?', there is an option 'Don't understand the question'. The same thing happens and we will make the question more effective for next time.