Answer:
B.) The chromosome carrying this gene changes shape during cell reproduction
Explanation:
According to this question, Sickle cell anemia is a genetic condition that occurs when the HBB gene that codes for haemoglobin protein undergoes a point mutation. Mutation alters the genetic sequence of a gene.
This mutation expresses itself when the chromosome 11 carrying the mutated gene changes shape during cell reproduction. Normal Red Blood Cell has a disc-shaped structure, however, this mutation causes a change in shape of the chromosome involved.