Which of the following best states the current AMDR for protein and its conceptual rationale relative to total daily calories?

15–50% of daily calories; a broad range intended to maximize muscle synthesis across the lifespan while allowing flexibility for different activity levels and body sizes, despite potential tradeoffs with carbohydrate and fat intake.

5–20% of total daily calories; chosen to minimize dietary cholesterol while ensuring minimal amino acid intake for survival in adults who are not growing.

10–35% of total daily calories; this range balances needs for maintenance, growth, and preventing excess displacement of other macronutrients.

25–60% of total calories; a guideline primarily focused on athletes and bodybuilders intended to prioritize protein over carbohydrates and fat to optimize lean mass gains under heavy resistance training conditions.