A study at Harvard University followed hundreds of people over the course of 75 years. What did they conclude about the quality of people’s relationships? A. It is the clearest predictor of someone’s overall physical health. B. It has very little effect on a person’s longevity and quality of life. C. It can eliminate mental health issues such as schizophrenia in children. D. It determines how often someone will need to get vaccinated in their life.