**Core Concept**
Iron-deficiency anemia is a condition characterized by a lack of sufficient iron to produce adequate hemoglobin, leading to reduced oxygen delivery to tissues. The initial response to iron therapy is a critical phase where the body's iron stores are replenished, and the production of red blood cells increases.

**Why the Correct Answer is Right**
The initial response to iron therapy in iron-deficiency anemia involves an increase in erythropoiesis, which is the production of red blood cells. This increase is mediated by the erythropoietin (EPO) pathway. EPO is a hormone produced primarily by the kidneys in response to low oxygen levels in the blood. It stimulates the bone marrow to produce red blood cells. As iron stores are replenished, the production of red blood cells increases, leading to an improvement in anemia.

**Why Each Wrong Option is Incorrect**
**Option A:** This option is incorrect because it does not accurately describe the initial response to iron therapy in iron-deficiency anemia. The initial response is not characterized by an increase in white blood cell count.

**Option B:** This option is incorrect because it is not a direct consequence of iron therapy in iron-deficiency anemia. While it is true that hemoglobin levels increase with iron therapy, this is a later effect rather than the initial response.

**Option C:** This option is incorrect because it is not a direct consequence of iron therapy in iron-deficiency anemia. The liver does play a role in iron metabolism, but the initial response to iron therapy is not characterized by an increase in liver enzymes.

**Clinical Pearl / High-Yield Fact**
The initial response to iron therapy in iron-deficiency anemia can be rapid, with improvements in hemoglobin levels and erythropoiesis evident within 2-4 weeks. This is a critical period where the body's iron stores are replenished, and the production of red blood cells increases.

**Correct Answer:** C. An increase in erythropoiesis is the initial response to iron therapy in a child suffering from iron-deficiency anemia.