Aristotle said that “happiness depends upon ourselves” and a new study suggests it is possible to physically grow a happier brain through practices like meditation (冥想). Although scientists have known which hormones (荷尔蒙) produce emotions like pleasure or desire, it has been unclear where the feeling of overall contentment and well-being originates from.

To find out, scientists asked 51 volunteers to rate their own happiness levels and then scanned their brains. Interestingly they discovered that an area of the brain called the precuneus (楔前叶) was larger in people who were happier. It suggests that happiness can be worked like a muscle.

What is the researchers’ attitude towards the finding?

A．Worried.

B．Doubtful.

C．Interested.

D．Optimistic.