**Core Concept**
Iron deficiency anemia is diagnosed based on a combination of clinical presentation, laboratory findings, and specific criteria. Mean corpuscular hemoglobin concentration (MCHC) is a crucial parameter in the diagnosis of iron deficiency anemia, as it reflects the concentration of hemoglobin within red blood cells.

**Why the Correct Answer is Right**
The MCHC is calculated by dividing the hemoglobin concentration by the mean corpuscular volume (MCV). In iron deficiency anemia, the MCHC is decreased due to the presence of small, pale red blood cells (microcytosis) with reduced hemoglobin content. This is because iron is essential for the production of hemoglobin, and its deficiency leads to impaired hemoglobin synthesis. The decreased MCHC is a specific criterion for diagnosing iron deficiency anemia.

**Why Each Wrong Option is Incorrect**
**Option A:** This option is incorrect as it fails to specify the correct MCHC value for diagnosing iron deficiency anemia. The correct value is not provided.
**Option B:** This option is incorrect as it mentions an elevated MCHC, which is not a characteristic of iron deficiency anemia. In fact, the MCHC is decreased in iron deficiency anemia.
**Option C:** This option is incorrect as it mentions a normal MCHC, which is not a specific criterion for diagnosing iron deficiency anemia. While the MCHC may be normal in some cases of iron deficiency anemia, it is not a reliable indicator.

**Clinical Pearl / High-Yield Fact**
In addition to MCHC, other laboratory findings such as low serum iron levels, decreased total iron-binding capacity (TIBC), and elevated ferritin levels are also important in diagnosing iron deficiency anemia.

**Correct Answer:** B. Less than 34 g/dL.