It is not controversial to say that an unhealthy diet causes bad health. Nor are the basic elements of healthy eating disputed. Obesity raises susceptibility to cancer, and Britain is the sixth most obese country on Earth. That is a public health emergency. But naming the problem is the easy part. No one disputes the costs in quality of life and depleted health budgets of an obese population, but the quest for solutions gets diverted by ideological arguments around responsibility and choice. And the water is muddied by lobbying from the industries that profit from consumption of obesity-inducing products.

    Historical precedent suggests that science and politics can overcome resistance from businesses that pollute and poison, but it takes time, and success often starts small. So it is heartening to note that a programme in Leeds has achieved a reduction in childhood obesity, becoming the first UK city to reverse a fattening trend. The best results were among younger children and in more deprived areas. When 28% of English children aged two to 15 are obese, a national shift on the scale achieved by Leeds would lengthen hundreds of thousands of lives. A significant factor in the Leeds experience appears to be a scheme called HENRY, which helps parents reward behaviours that prevent obesity in children.

    Many members of parliament are uncomfortable even with their own government’s anti-obesity strategy, since it involves a “sugar tax” and a ban on the sale of energy drinks to under-16s. Bans and taxes can be blunt instruments, but their harshest critics can rarely suggest better methods. These critics just oppose regulation itself.

    The relationship between poor health and inequality is too pronounced for governments to be passive about large-scale intervention. People living in the most deprived areas are four times more prone to die from avoidable causes than counterparts in more affluent places. As the structural nature of public health problems becomes harder to ignore, the complaint about overprotective government loses potency.

    In fact, the polarised debate over public health interventions should have been abandoned long ago. Government action works when individuals are motivated to respond. Individuals need governments that expand access to good choices. The HENRY programme was delivered in part through children’s centres. Closing such centres and cutting council budgets doesn’t magically increase reserves of individual self-reliance. The function of a well-designed state intervention is not to deprive people of liberty but to build social capacity and infrastructure that helps people take responsibility for their wellbeing. The obesity crisis will not have a solution devised by left or right ideology—but experience indicates that the private sector needs the incentive of regulation before it starts taking public health emergencies seriously.

解析：A。根据题干中的public health emergencies可定位到原文第一段第四句。该句指出英国的肥胖问题属于公共卫生紧急事件。随后再根据题干中的the past experience可定位到第二段第一句。该句指出，历史前例表明，对于一些污染和毒害企业制造的阻力，科学和政治是可以克服的，但是需要时间，而且成功往往是从小事开始的。该句说明了政治可以在公共卫生紧急事件中起到作用，故正确答案为A项。

错项排除：原文第二段第一句虽然也提到科学在卫生事件中的作用，但并没有将公共卫生事件直接定义为科学问题，故B项排除。C项用deprived设置干扰，该词在第二、四段中出现。第二段中主要是说利兹的项目在贫困地区效果显著；第四段只是陈述了贫困地区面临的健康安全问题更大，并没有提到应该优先考虑贫困地区，故C项排除。D项中的Businesses在第二段第一句提及，但该句重点是说科学和政治能克服一些企业带来的阻力，并不是强调企业的责任，故D项错误。