Read the following passage and mark the letter A, B, C or D on your answer sheet to indicate the correct answer to each of the questions fro...

Read the following passage and mark the letter A, B, C or D on your answer sheet to indicate the correct answer to each of the questions from 11 to 18.

        Genetics has a much larger role in how long a person lives than previously thought, challenging decades of scientific consensus. About 55% of the human lifespan is heritable, meaning that more than half of the variation in longevity across a population is attributable to genetics. This is a much greater proportion than previous estimates of 10–25%, suggesting that genetics is a primary factor in the ageing process.

        Previous estimates were too low because they did not effectively separate deaths caused by extrinsic factors, such as accidents, from intrinsic ones inside the body. To tease out these factors, researchers re-examined data from twin studies in Denmark and Sweden. By comparing identical twins, who share all their DNA, with fraternal twins, the team could accurately model the portion of lifespan determined specifically by genes.

        Excluding deaths caused by extrinsic factors made the similarity in lifespans between genetically related individuals much clearer. This connection became more apparent over time owing to improved public-health measures. In data from the late 1800s, when people often died young from infections, the genetic signal was almost invisible. However, the calculated heritability rose naturally over the twentieth century as medical advancements reduced external risks.

        Not all intrinsic causes of death are equally heritable; while cardiovascular disease showed high genetic influence, cancer showed much lower heritability, likely driven by environmental triggers. These results do not indicate a genetically encoded “destiny,” because healthy living is still heavily influenced by lifestyle choices. You cannot change the genes you are born with, but you can change your lifestyle to ensure you live a longer, healthier life.

(Adapted from https://www.nature.com/)

Question 11. According to paragraph 1, genetic factors ____________.

        A. account for more than half of the variation in how long people live

        B. used to be widely overestimated among the scientific community

        C. play an important role in reducing the speed of the ageing process

        D. have various effects on longevity across different population groups