The nurse is trying to offer assistance to the family of a dying child. The nurse can:

A. Thrombocytopenia: Thrombocytopenia is a condition characterized by a low platelet count, and it is not a typical feature of iron-deficiency anemia.

B. Increased Total Iron-binding Capacity: In iron-deficiency anemia, the Total Iron-binding Capacity (TIBC) is typically increased as the body attempts to compensate for the low iron levels by increasing its capacity to bind and transport iron.

C. Decreased Folate Levels: While iron-deficiency anemia and folate-deficiency anemia are both forms of anemia, decreased folate levels are more characteristic of folate-deficiency anemia, which is a separate condition.

D. Microcytic Red Blood Cells.

Iron-deficiency anemia is characterized by a decrease in the body's iron stores, which in turn affects the production of hemoglobin and red blood cells. This results in the formation of microcytic (smaller than normal) red blood cells. These smaller red blood cells are a typical finding in iron-deficiency anemia.

A. Shunted past the pulmonary circulation, causing pulmonary hypoxia: This option is not the primary reason for dyspnea in PDA. While there is shunting, it doesn't directly cause pulmonary hypoxia.

B. Circulated through the lungs again, causing pulmonary circulatory congestion: This option is partially correct but does not address the primary reason for dyspnea, which is the bypassing of the left side of the heart.

C. Circulated through the ductus from the pulmonary artery to the aorta, bypassing the left side of the heart.

In patent ductus arteriosus (PDA), a fetal blood vessel called the ductus arteriosus fails to close after birth. This allows oxygenated blood from the left atrium to be shunted directly from the aorta to the pulmonary artery, bypassing the normal route through the left side of the heart and into the systemic circulation. The shunting of oxygenated blood back into the pulmonary circulation can lead to increased pulmonary blood flow and circulatory congestion, causing symptoms such as dyspnea.

D. Shunted past cardiac arteries, causing myocardial hypoxia: PDA primarily affects the pulmonary circulation and left side of the heart, not the coronary arteries. Myocardial hypoxia is not the primary mechanism of dyspnea in PDA.