This is irrelevant to the question of whether the foods featured on television influence viewers’ dietary habits. As in (C), we don’t care why the foods are featured, just what impact they have.

In other words, seeing low-nutritional-value foods on television leads viewers to eat more of those foods, thus worsening their diets. Without this assumption linking television content to poor dietary habits, the argument wouldn’t make sense.

Like (A), this focuses on the irrelevant consideration of why certain foods are featured on television. But we don’t need to know why, we only need to know if featuring certain foods can impact viewers’ eating habits.

Whether or not television characters’ dietary habits are interesting to viewers is irrelevant, because it doesn’t get to whether those dietary habits can actually impact viewers’ own dietary habits.

Even if the foods featured on television can help to predict what foods will become popular, that doesn’t tell us that television has a bad influence. To get to that conclusion, we would need to assume that television leads people to eat worse foods, not just different foods.