Researchers in the psychology department at the University of California at Los Angeles (UCLA) have discovered a major difference in the way men and women respond to stress. This difference may explain why men are more likely to suffer from stress-related disorders.
Until now, psychological research has maintained that both men and women have the same "fight-or-flight" reaction to stress. In other words, individuals either react with aggressive behavior, such as verbal or physical conflict ("fight"), or they react by withdrawing from the stressful situation ("flight"). However, the UCLA research team found that men and women have quite different biological and behavioral responses to stress. While men often react to stress in the fight-or-flight response, women often have another kind of reaction which could be called "tend and befriend." That is, they often react to stressful conditions by protecting and nurturing their young ("tend"), and by looking for social contact and support from others - especially other females ('befriend").
Scientists have long known that in the fight-or- flight reaction to stress, an important role is played by certain hormones(激素) released by the body. The UCLA research team suggests that the female tend-or-befriend response is also based on a hormone. This hormone, called oxytocin, has been studied in the context of childbirth, but now it is being studied for its role in the response of both men and women to stress. The principal investigator, Dr. Shelley E. Taylor, explained that "animals and people with high levels of oxytocin are calmer, more relaxed, more  social, and less anxious." While men also secrete(分泌）oxytocin, its effects are reduced by male hormones.
In terms of everyday behavior, the UCLA study found that women are far more likely than men to seek social contact when they are feeling stressed. They may phone relatives or friends, or ask directions if they are lost.
The study also showed how fathers and mothers responded differently when they came home to their family after a stressful day at work. The typical father wanted to be left alone to enjoy some peace and quiet. For a typical mother, coping with a bad day at work meant focusing her attention on her children and their needs.
The differences in responding to stress may explain the fact that women have lower frequency of stress-related disorders such as high blood pressure or aggressive behavior. The tend-and-befriend regulatory(调节的) system may protect women against stress, and this may explain why women on average live longer than men.
The UCLA study shows that in response to stress, men are more likely than women to _____ .

A．turn to friends for help	B．solve a conflict calmly
C．find an escape from reality	D．seek comfort from children

Which of the following is true about oxytocin according to the passage?

A．Men have the same level of oxytocin as women do.

B．Oxytocin used to be studied in both men and women.

C．Both animals and people have high levels of oxytocin.

D．Oxytocin has more of an effect on women than on men.

What can be learned from the passage?

A．Male hormones help build up the body's resistance to stress.

B．In a family a mother cares more about children than a father does.

C．Biological differences lead to different behavioral responses to stress.

D．The UCLA study was designed to confirm previous research findings.

Which of the following might be the best title of the passage?

A．How men and women get over stress

B．How men and women suffer from stress

C．How researchers overcome stress problems

D．How researchers handle stress-related disorders