Answer:
They can influence the mass media
Step-by-step explanation:
Public Agenda is the issue that most people in the country will be focused on. This could include both economic, socio-cultural, or foreign relations.
Every times the national government propose a certain bill or regulation to handle a certain issue, the media will pick up on it.
When the news is presented to the public, a nationwide conversation will occurs among the citizens to discuss that topic. Some might support it, while some might oppose to it.
This will eventually form a popular public opinion regarding how we as a nation could address the issue, and a public agenda is formed.