单选题：Questions are based on the following passage．Life is pricele

Questions are based on the following passage．
Life is priceless to those who possess it. Policymakers, though, must take a morehard-headed ( 头脑冷静的 ) approach. That is particularly--if unfairly--true in poorerparts of the world. It is important for the authorities to understand the cost-effectiveness ( 成本效益) of a health programme, so that its value can be compared with that of otherclaims on the public purse.
How to go about doing this is illustrated by a paper published in the PublicLibrary of Science by Kartik Venkatesh of Brown University and Jessica Becker ofYale. Dr. Venkatesh and Dr. Becker asked themselves if it would be a good idea for thegovernment of India to try, at regular intervals, to test the country's population for HIV,the virus that causes AIDS, in order to treat those who unknowingly harbour it. The shortanswer is that, if it were feasible, it would be.
Though HIV in India has not turned into the widespread epidemic some expertsfeared it would a few years ago, it is reckoned to affect about 2.4m people, many ofwhom do not realise they are infected. If they were identified, these people could be givenantiretroviral ( 抗逆转录病毒的 ) drugs to stop the symptoms of AIDS developing. Thatwould also have the bonus of reducing the chance of their passing the virus on.
The calculations made by Dr. Venkatesh and Dr. Becker rely on a model developedby the World Health Organisation and already in use in America, France, South Africa andelsewhere. It values lives extended and saved, and further infections and other treatmentavoided. It then balances those against the costs of testing people and of giving drugs tothose who test positive (plus the inevitable extra non-HIV spending that typically followstesting).
The price at which an extra year of life saved is deemed cost-effective is anythingless than triple the annual GDP per person of the country in question. In India that is $3,900.
Anything below parity ($1,300 per year of life) counts as very cost-effective. According toDr. Venkatesh and Dr. Becker, testing Indian adults every five years would cost $1,900 peryear of life saved, and would thus pay off handsomely.
Whether it could actually be done is another matter. But India takes AIDS seriouslyand the fact that the epidemic has not run out of control in the way that was once fearedis at least in part the consequence of the country's policies. The will to test thereforeprobably exists. Dr. Venkatesh and Dr. Becker suggest it would be worth finding themeans, as well.
What do we know about the paper written by Dr. Venkatesh and Dr. Becket? A．It explained how to value a health programme.
B．It was published in the Public Liberty of Science.
C．It aimed to prevent the spread of AIDS in India.
D．It suggested India should test its people for HIV annually.