Final answer:
Thad should focus on how he will minimize the distraction of texting to support his case for being responsible enough to have a cell phone.
Step-by-step explanation:
Thad should develop key idea number 3, how he will minimize the distraction of texting, to support his thesis that he is responsible enough to have a cell phone. This point is crucial because his parents' primary concern is that a phone would become a distraction. By addressing this concern directly, Thad can provide a problem-solution reasoning approach, showing that he has considered potential issues and is actively finding ways to mitigate them.
This might involve setting specific times for texting, using app limits to control his screen time, or creating a schedule that prioritizes his responsibilities before socializing. By elaborating on this strategy to prevent texting from becoming a distraction, Thad appeals to his parents' desire for him to be responsible and focused, demonstrating that he's thoughtfully considered the implications of owning a phone.