Thalassemia and sickle cell anaemia are caused due to a problem in globin molecule synthesis. Select the correct statement.

Thalassemia is a rare inherited blood disorder which is caused due to inadequate amounts of haemoglobin synthesis in humans due to mutation in the gene coding haemoglobin. The defect can occur due to mutation or deletion of the genes encoding the globin chains of haemoglobin, which leads to its decreased production. Hence, less amounts of haemoglobin is synthesised by the body. So, it is a quantitative disorder. Option b is correct.
Sickle cell anaemia is caused due to mutation in the gene encoding haemoglobin which results in abnormal haemoglobin synthesis. Here, haemoglobin is produced but the mutation results in change in shape of RBCs. It is a qualitative disorder. Option a,c, and d are incorrect.