Human resources focus on workforce size and skills, not land.

Steps:

• Define human resources as the population's labor capacity, measured by quantity (number of workers) and quality (skills, health).
• Assess each option: A, B, and C enhance skills, health, or nutrition, directly improving human resources.
• Evaluate D: Land reclamation expands physical territory, affecting natural resources instead.
• Conclude the action not directly impacting human resources is D.

Why D is correct:

• Human resources in economics refer to labor supply and productivity; land reclamation increases natural capital (e.g., arable land) per the factors of production model, not human factors.

Why the others are wrong:

• A: Boosts skills and knowledge, enhancing workforce quality.
• B: Improves physical well-being, increasing worker efficiency and longevity.
• C: Enhances nutrition, supporting population health and growth for better quantity and quality.

Final answer: D