The correct answer is: a school-aged child.
Media stereotypes refer to archetypal characters found in media, such as TV shows and movies. These archetypal characters- such as: a powerful CEO, a computer geek, or a controlling housewife- are commonly found in media, and they represent simplistic stereotypes and ideas that are commonly associated with the character they represent. For instance, a controlling housewife is represented as a woman who is neurotic, suspicious of her husband's whereabouts, controlling and dominating over her children, and so on.
From the options included, a school-aged child is least likely to be used as a media stereotype, because a a school-aged child is too broad of a character to have stereotypes associated with it. What is more likely to be used as a media stereotype would be a shy, and socially awkward school-aged child.