Concept:Pressure groups are organised bodies that seek to shape government decisions without holding formal power.Explanation:In a democracy, pressure groups use methods like lobbying, protests, and public campaigns to push their interests.Their main aim is not to implement policies themselves, but to persuade or pressurise the government to make decisions that favour their members or causes.Thus, their pivotal role is to influence public policy decisions from outside the formal structure of government.Answer:B. influence on public policy decisions