Given below are six sentences taken from a paragraph. The first and the last sentences are numbered S1 and S2 and are placed in the first and last positions respectively and are fixed in their positions. The other four sentences between the first and last sentences are jumbled up and are numbered A, B, C, and D. Rearrange the jumbled sentences in a logical sequence keeping the unity and coherence of the paragraph intact. Choose the correct alternative that best describes the sequence.
S1. Babies were frequently exposed to polioviruses.
A. Paradoxically, when sanitation improved, infants were no longer exposed at an age when they were protected, so they did not develop antibodies to the viruses.
B. The babies then developed their own antibodies to the virus.
C. Consequently, when they were exposed to the virus in later childhood and adulthood, they were at risk to contract polio.
D. These infants did not contract the disease because their mothers' antibodies were passed on to them through breast-feeding.
S2. This understanding about the nature of polio grew through painstaking research over the first half of the twentieth century, much of it funded by the March of Dimes, a grassroots organization founded with the help of President Roosevelt.
Show answer & explanation
Correct answer: B
Explanation
Correct Answer
DBAC
Explanation
The correct sequence is DBAC because it presents the idea in a logical cause-and-effect order. After stating that babies were frequently exposed to polioviruses (S1), sentence D explains why they did not develop the disease—they were protected by antibodies received through breast-feeding. Sentence B naturally follows, stating that the babies then developed their own antibodies. Sentence A introduces the change brought about by improved sanitation, which prevented early exposure to the virus. Finally, sentence C explains the consequence of this change: people became vulnerable to polio when exposed later in childhood or adulthood.
The other sequences fail to maintain the logical progression of protection, immunity, change in exposure, and its resulting risk.
Key Point
In paragraph rearrangement questions, look for cause-and-effect relationships and connecting words such as "then," "paradoxically," and "consequently." These transition words often indicate the correct order of ideas and help establish a coherent flow of the passage.