As William Chopik, associate professor...

Câu hỏi: As William Chopik, associate professor of psychology and author of the study says: “Friends are a conscious choice. Family relationships can be serious, negative and monotonous." The research included two studies - one a broad survey of nearly 300,000 people, aged between 15 and 99, from more than 90 countries. This study found that those (25) ______valued friendships highly were healthier and happier (according to their own reports), especially as they got older. The second study used data from a US survey of 7,481 people over 50. Subjects were questioned about the quality of their friendships - how much friends understood them and how much they let them down.

A. highly    

B. high        

C. higher     

D. highest