单选题：Marriage and Life SpanBeing sociablelooks like a good way to

Marriage and Life Span Being sociablelooks like a good way to add years to your life. Relationships with family,friends, neighbours, even pets, will all do the trick, but the biggestlongevity (长寿) boostseems to come from marriage or an equivalent relationship. The effect was firstnoted in 1858 by William Farr, who wrote that widows (寡妇) and widowers (鳏夫) were at a much higher risk ofdying than their married peers. Studies since then suggest that marriage couldadd as much as seven years to a man’s life and two to a woman’s. The effectholds for all causes of death, whether illness, accident or self-harm.
　　Even if the oddsare stacked against you, marriage can more than compensate. Linda Waiteof the University of Chicago has found thata married older man with heart disease can expect to live nearly four yearslonger than an unmarried man with a healthy heart. Likewise, a married man whosmokes more than a pack a day is likely to live as long as a divorced man whodoesn’t smoke. There’s a flip side, however, as partners are more likely tobecome ill or die in the couple of years following their spouse’s death, andcaring for a spouse with mental disorder can leave you with some of the samesevere problems. Even so, the odds favour marriage. In a 30-year study of morethan 10,000 people, Nicholas Christakis of Harvard Medical School describes how allkinds of social networks have similar effects.
　　So how does itwork? The effects are complex, affected by socio-economic factors,health-service provision, emotional support and other more physiological mechanisms. For example, social contact can boostdevelopment of the brain and immune system, leading to better health and lesschance of depression later in life. People in supportive relationships mayhandle stress better. Then there are the psychological benefits of a supportivepartner.
　　A life partner,children and good friends are all recommended if you aim to live to 100. Theultimate social network is still being mapped out, but Christakis says: “Peopleare interconnected, so their health is interconnected.”
根据以上内容，回答题。
According tothe first paragraph, William Farr’s study and other studiesshow that
A) social lifeprovides an effective cure for illness
B) being sociablehelps improve one’s quality of life
C) women benefitmore than men from marriage
D) marriagecontributes a great deal to longevity