A、A study on whether social connections can keep us healthier. B、A study on whether social connections make us happier. C、A stud

Humans are social animals, and most of us treasure our relationships with family and friends. An emerging line of research suggests that relationships can keep us healthier. And a new study finds those social connections may also help us live longer. This new study combined a large number of previous studies and concluded that a lack of social interactions ranks right up with smoking, obesity, and alcoholism as a risk factor for death. Researchers from Brigham Young University analyzed 148 studies with a total of some 300,000 participants, tracking their social relationships and whether they survived to the end of their particular study, which averaged about seven years. "Those who scored higher on those measures of social relationships were 50 percent more likely to be alive at that follow-up than people who scored low on those measures," said Professor Julianne Holt-Lunstad, one of the authors of the study. She pointed out several ways relationships can affect our health. They can help us cope with stress. They can help us maintain healthy habits like eating well, exercising or seeing a doctor. And there’s increasing research that shows a direct but poorly-understood link between relationships and physiological processes in the body. "So for instance, our relationships have been linked to lower blood pressure, better immune functioning, and even inflammatory processes that are implicated in a number of diseases," said Holt-Lunstad. "And so our relationships can influence our health in a variety of ways that are all very important." Julianne Holt-Lunstad said her research suggests that policy makers need to consider relationships as a health issue.
Questions 26 to 28 are based on the passage you have just heard.
26. What is the passage mainly about?
27. How many participants were involved in the study?
28. What does Julianne Holt-Lunstad’s research suggest?