Read the article and select the best answer. Article: Elderly adults who regularly drink green tea may stay more agile and independent than their peers over time, according to a Japanese study that covered thousands of people. Green tea contains antioxidant chemicals that may help stop the cell damage that can lead to disease. Researchers have been studying green tea's effect on everything from cholesterol to the risk of certain cancers, with mixed results so far. They found those who drank the most green tea were the least likely to develop "functional disability", or problems with daily activities or basic needs, such as dressing or bathing. Specifically, almost 13 percent of adults who drank less than a cup of green tea per day became functionally disabled, compared with just over 7 percent of people who drank at least five cups a day. The study did not prove that green tea alone kept people agile as they grew older. Green-tea lovers generally had healthier diets, including more fish, vegetables and fruit, as well as more education, lower smoking rates, fewer heart attacks and strokes, and greater mental sharpness. They also tended to be more socially active and have more friends and family to rely on. But even with those factors accounted for, green tea itself was tied to a lower disability risk, the researchers said. People who drank at least five cups a day were one-third less likely to develop disabilities than those who had less than a cup per day. Those people who averaged three or four cups a day had a 25 percent lower risk. Although it's not clear how green tea might offer a buffer against disability, Tomata's team did note that one recent study found green tea extracts seem to increase leg muscle strength in older women. While green tea and its extracts are considered safe in small amounts, they do contain caffeine and small amounts of vitamin K, which means it could affect drugs that prevent blood clotting . Question: What can be learned from the passage? Options: A: Antioxidant chemicals can lead to disease. B: Those who often drank green tea can't develop "functional disability". C: "Functional disability" is related to problems with daily activities or basic needs. D: People who drank at least five cups a day are not likely to become functionally disabled.
Answer:
C