**Core Concept**
Cooley's anemia is a severe form of thalassemia major, a genetic disorder affecting hemoglobin production. It is characterized by the production of abnormal hemoglobin, leading to severe anemia, bone deformities, and other complications.

**Why the Correct Answer is Right**
Cooley's anemia is caused by mutations in the HBB gene, which codes for the beta-globin subunit of hemoglobin. This leads to the production of abnormal beta-globin chains, resulting in the formation of abnormal hemoglobin (HbS or HbF) and subsequent anemia. The disease is inherited in an autosomal recessive pattern, meaning that a person must inherit two defective copies of the gene (one from each parent) to develop the condition. The name "Cooley's anemia" is attributed to Thomas Cooley, who first described the condition in 1920.

**Why Each Wrong Option is Incorrect**
**Option A:** Sickle Cell Anemia - While both conditions affect hemoglobin production, they are distinct genetic disorders caused by different mutations (HBB gene vs. HBA1/HBA2 genes).

**Option B:** Beta Thalassemia Intermedia - This is a milder form of thalassemia, characterized by a partial deficiency of beta-globin production.

**Option C:** Alpha Thalassemia Major - This condition is caused by mutations in the HBA1/HBA2 genes, affecting alpha-globin production, and is distinct from Cooley's anemia.

**Clinical Pearl / High-Yield Fact**
It's essential to remember that Cooley's anemia is a severe form of thalassemia major, requiring regular blood transfusions, iron chelation therapy, and other supportive care measures to manage symptoms and prevent complications.

**Correct Answer:** D.