The correct answer is option 1: Genetic disorder. Sickle cell anemia is a type of genetic disorder that affects the red blood cells. It is inherited through the genes passed down from parents to their children.

To understand why sickle cell anemia is a genetic disorder, we need to understand a bit about genetics. Our genes contain instructions for making proteins that are essential for our body`s development and functioning. One particular gene that is affected in sickle cell anemia is responsible for making a protein called hemoglobin, which helps carry oxygen in the blood.

In individuals with sickle cell anemia, a mutation occurs in the hemoglobin gene, leading to the production of abnormal hemoglobin. This abnormal hemoglobin causes the red blood cells to become sickle-shaped, instead of their usual round shape. These sickle-shaped red blood cells are less flexible and can become stuck in blood vessels, leading to a range of health problems.

It is important to note that sickle cell anemia is not caused by a virus, bacteria, or vitamin deficiency. It is a specific genetic condition that is inherited from parents.