In the question below, a sentence is given, divided

Solution

(e) is the right answer as AEBC is the correct sequence and part D is the odd part. B begins by establishing the subject of the sentence as the basis of vaccination- in a generic sense, vaccination works by priming the immune system then E continues by telling us what should be introduced to make vaccine work- with an 'immunogen'. B continues by telling us the immunogen develops immunity to the disease. C concludes by telling us how immunity against polio virus help us to prevent person-to-person transmission of wild poliovirus. D is the odd part as it talks about research done in the field of polio virus - no researchers dared attempt a polio vaccine for 20 years and has not been discussed in any other part, it fails to link itself coherently with any of the other parts of the sentence.