The Comparison of the Amino Acid Sequences of Cytochrome C

The comparison of the amino acid sequences of cytochrome c (see Figure 24.3) from plants to human showed that

A) gaps and/or insertions were required in some cases to optimize the alignment.
B) there were very few invariant amino acids in the sequence.
C) the least variable regions were at the ends of the molecule.
D) there was little change in all parts of the molecule.
E) the amino acids with side chains that bind the heme were variable.