A、5 gms. B、10 gms. C、15 gms. D、50 gms. B文中提到“the safety threshold for sugar would be 10gms a day”，threshold在这里表示“许可量”，与limit相近，由

The World Health Organization is to call for strict controls on junk food in a major campaign against obesity, and the agency will unveil its actual strategy next week. Based on evidence obtained through various investigations, the WHO believes that obesity has become a global epidemic that is directly associated with more than 30 million deaths each year. According to the agency, obesity is now one of the world’s three greatest health threats, along with smoking and malnutrition. Recent estimates suggest that 1.7 billion people are now obese, which has led to a surge in diseases such as cancers and diabetes.
    The WHO will call for heavy cuts in the use of sugar, salt and saturated fats. And this is bound to sound the alarm to many of Britain’s top-selling brands, including Cadbury’s, Coca-Cola, and Birds Eye. The WHO will produce a policy paper calling for new daily limits for sugar, salt and fats, as well as tougher control of food advertising. According to the figures issued by the WHO, the safety threshold for sugar would be 10gms a day—a limit already exceeded by one 500ml bottle of cola and, salt should be limited to 5gms a day—the amount of salt contained in a standard tin of baked beans.