**Core Concept**
The patient's laboratory findings indicate microcytic anemia, characterized by a low Mean Corpuscular Volume (MCV) of 60 fL, which is below the normal range of 80-100 fL. This is accompanied by a low hemoglobin (Hb) level of 5 gm%, a low Mean Corpuscular Hemoglobin Concentration (MCHC) of 20 g/dL, and a low Packed Cell Volume (PCV) of 32%.

**Why the Correct Answer is Right**
Microcytic anemia is caused by a reduction in the size of red blood cells, which can be due to several factors. One possible cause is iron deficiency anemia, which occurs when there is a lack of iron available for hemoglobin synthesis. This can be due to inadequate dietary intake, increased demand for iron, or chronic blood loss. The low MCHC in this patient suggests that the red blood cells are not able to carry enough hemoglobin, which is consistent with iron deficiency anemia.

**Why Each Wrong Option is Incorrect**
**Option A:** Sickle cell anemia would typically present with a high MCHC, as the red blood cells are abnormally shaped and contain more hemoglobin than normal cells.

**Option B:** Macrocytic anemia would have a high MCV, as the red blood cells are larger than normal.

**Option C:** Normocytic anemia would have a normal MCV, as the red blood cells are of normal size.

**Clinical Pearl / High-Yield Fact**
Remember the "3 Ps" of microcytic anemia: Pernicious anemia (due to vitamin B12 deficiency), Porphyria (due to lead poisoning), and Poor diet (due to iron deficiency).

**Correct Answer: A. Iron deficiency anemia.**