Comparing "Popular Problems" to "Free" in terms of how they explore the theme of identity, the most suitable response is:
a) Both texts show characters struggling with how others perceive them versus how they see themselves.
This option captures the essence of the characters' internal conflicts regarding their identities. In the excerpt provided, Randall initially feels envious of Starks and his perceived wealth and popularity, reflecting how external perceptions can influence a person's self-esteem and identity. As the story progresses, Randall begins to recognize the complexity of Starks' life, realizing that identity is not solely defined by wealth or popularity, but also by personal connections and kindness. This suggests that both texts likely delve into similar themes, illustrating the struggle between public perception and personal identity.
Other responses, such as those focusing on financial success or self-doubt, do not fully encapsulate the exploration of identity in both texts as effectively as option (a) does.