A Sequence of Amino Acids Found in a Subunit of the ATP

A sequence of amino acids found in a subunit of the ATP synthase enzyme in several species is shown below.Which amino acids are likely to be most important to the function of ATP synthase?

A) Those that are shaded dark blue because the amino acids are identical between species.
B) Those that are shaded light blue because the amino acids are similar, but not identical.
C) Those that are not shaded because the amino acid sequences are different between species.
D) Comparing sequence between species does not indicate which amino acids are important to function.