Sickle Cell Is a Codominant Disease, Meaning That Heterozygotes Exhibit

Sickle cell is a codominant disease, meaning that heterozygotes exhibit an intermediate blood cell phenotype (a mixture of normal and sickle cells) due to the blend of hemoglobin tetramers in each red blood cell. Which of the following tetramer structures would you expect to find in a carrier of SCD?

A) α₂β^A₂
B) α₂β^Sβ^A
C) α₂β^S₂
D) α₂β^A₂ and α₂β^Sβ^A
E) α₂β^A₂ and α₂β^Sβ^A and α₂β^S₂