单选题：请阅读下面材料,完成第小题。 Being sociable looks like a good way to add

请阅读下面材料,完成第小题。
Being sociable looks like a good way to add years to your life．Relationships with family，friends，neighbors，even pets，will all do the trick，but the biggest longevity boost seems to come from marriage or an equivalent relationship．The effect WaS first noted in 1 858 by William Farr，who wrote that widows and widowers(鳏夫)were at a much higher risk of dying than their married peers．Studies since then suggest that marriage could add as much as seven years to a man’s life and two to a woman’s．The effect holds for all causes of death，whether illness，accident or self-harm．
Even if the odds are stacked against you，marriage can more than compensate．Linda Waite of the University of Chicago has found that a married older man with heart disease Call expect to live nearly four years longer than an unmarried mall with a healthy heart．Likewise，a married man who smokes more than a pack a day is likely to live as long as a divorced man who doesn’t smoke．
There’S a flip side，however，as partners are more likely to become ill or die in the couple of years following their spouse’S death，and caring for a spouse with mental disorder can leave you with some of the same severe problems．Even S0，the odds favor marriage．In a 30-year study of more than l0 thousand people，Nicholas Christakis of Harvard Medical School describes how all kinds of social networks have similar effects．
So how does it work?The effects are complex，affected by socio-economic factors，health-selw．ice provision，emotional support and other more physiological mechanisms．For example。social con-tact can boost development of the’brain and immune system，leading to better health and less chance of depression later in life．People in supportive relationships may handle stress better．Then there are the psychological benefits of a supportive partner．
A life partner，children and good friends are all recommended if you aim to live to 100．The ul-timate social network is still being mapped out，but Christakis says：“People are interconnected，SO tileir health i8 interconnected．”
William Farr's study and other studies show that__________． A．social life provides an effective cure for illness
B．being sociable helps improve one’s quality of life
C．women benefit more than men from marriage
D．marriage contributes a great deal to longevity