Which of the following doesn’t describe PAM matrices?

• A. This family of matrices lists the likelihood of change from one amino acid to another in homologous protein sequences during evolution
• B. There is presently no other type of scoring matrix that is based on such sound evolutionary principles as are these matrices
• C. Even though they were originally based on a relatively small data set, the PAM matrices remain a useful tool for sequence alignment
• D. It stands for Percent Altered Mutation