Based on the number of differences in amino acid sequence, which pair of organisms is least related to each other?

Question: Based on the number of differences in amino acid sequence, which pair of organisms is least related to each other?

The protein molecule called cytochrome c which serves a vital function in respiration within cells consists of the same 104 amino acids in exactly the same order. This means that the hagfish is the least related to the other organisms. Humans are most closely related to the monkey there is only one amino acid difference between the two.