A
[解析] 根据文章第二段第三、四、五句“If half the energy that goes into violent acts were put to good use, if our efforts were directed at cleaning up the slums and ghettos, at improving living-standards and providing education and employment for all, we would have gone a long way to arriving at a solution. Our strength is undermined by having to mop up the mess that violence leaves in its wake. In a well-directed effort, it would not be impossible to fulfill the ideals of a stable social program.”可知,在作者看来,如果能把实施暴力的一半精力用于清理贫民窟、改善人民生活水平、创造就业和受教育机会,经过长期努力,会取得有意义的成果的。据此判断,答案是A。