Final answer:
The main idea of the given text is that propaganda is used to persuade public opinion, with statement (1) clearly defining this concept.
Step-by-step explanation:
The main idea of the text is that propaganda is a strategic form of communication used to influence people's attitudes and beliefs toward a specific cause or position. Often, it incorporates various techniques such as bandwagon, testimonials, plain-folk appeals, and transfer, to persuade and manipulate public opinion. In the given text, statement (1) encapsulates the central concept by defining propaganda and its purpose, making it the main idea around which the other statements revolve. The remaining sentences (2) through (11) serve to elaborate on this main idea by providing examples and details about different propaganda techniques.