Key Concept: Iron-deficiency anemia symptoms trace directly back to reduced oxygen transport in the blood.
Why it's correct: Without enough iron, hemoglobin production drops, so less oxygen reaches body tissues — causing fatigue, weakness, and pale skin.
Why others fail: Jaundice signals liver issues, hyperactivity isn't a recognized anemia symptom, and weight gain is unrelated — none connects to reduced oxygen transport the way fatigue does.