Answer:
Mass society era
Step-by-step explanation:
During the mass society era, which took place in the mid-20th century, advertising and national brands emerged as a result of several factors. The growth of mass media, such as radio and television, allowed for the widespread dissemination of advertising messages to a large audience. This era was characterized by the rise of consumer culture, where people became more focused on acquiring material possessions and brands played a significant role in shaping people's identities and social status. National brands became prominent symbols of quality and reliability, and advertising played a key role in promoting these brands and creating a desire for their products among consumers.