**Core Concept**
Beta-thalassemia minor is a genetic disorder characterized by reduced production of the beta-globin chains of hemoglobin. This condition results from mutations in the HBB gene, leading to impaired beta-globin synthesis.

**Why the Correct Answer is Right**
In beta-thalassemia minor, the main abnormality is a reduction in the production of the beta-globin chains, resulting in a decreased amount of normal adult hemoglobin (HbA). This leads to a compensatory increase in the production of alpha-globin chains, which then form abnormal hemoglobins such as HbA2 and hemoglobin A2 (HbA2). The impaired beta-globin synthesis is due to mutations in the HBB gene that affect the transcription or translation of the beta-globin mRNA.

**Why Each Wrong Option is Incorrect**
* **Option A:** This option does not accurately describe the main abnormality in beta-thalassemia minor.
* **Option B:** This option is incorrect as the main abnormality in beta-thalassemia minor is not an increase in beta-globin chains.
* **Option C:** This option does not accurately describe the main abnormality in beta-thalassemia minor.

**Clinical Pearl / High-Yield Fact**
Beta-thalassemia minor can be distinguished from beta-thalassemia major by the presence of a normal or near-normal amount of hemoglobin A, despite the presence of abnormal hemoglobins such as HbA2.

**Correct Answer: C. Reduced production of beta-globin chains.**