Which of the following is true for given diagram

The correct option is C B is Valine
Sickle cell disease (SCD) is a group of blood disorders typically inherited from a person's parents. The most common type is known as sickle cell anaemia (SCA). It results in an abnormality in the oxygen-carrying protein haemoglobin found in red blood cells. This leads to a rigid, sickle-like shape under certain circumstances. The gene defect is a single nucleotide mutation (GAG codon changing to GTG) of the β-globin gene, which results in glutamic acid (Glu) being substituted by valine (Val) at position 6.