The Difference Between Normal Hemoglobin and Sickle-Cell Hemoglobin Is in the

The difference between normal hemoglobin and sickle-cell hemoglobin is in the

A) heme portion of the molecules.
B) number of chains of amino acids.
C) substitution of a specific amino acid for another specific amino acid.
D) addition of one amino acid to the normal hemoglobin molecule.
E) deletion of only one amino acid from the normal hemoglobin molecule.