HIV, the virus that causes AIDS, was isolated from three individuals, and the amino acid sequences for the viral coat were determined. Of the amino acid sequences shown below, which two of the viruses are most closely related? How can these amino acid sequences be used to identify the source of the virus?
Patient.....Viral Amino Acid Sequence
A.....Asn Gln Thr Ala Ala Ser Lys Asn Ile Asp Ala Leu
B.....Asn Leu His Ser Asp Lys Ile Asn Ile Ile Leu Leu
C.....Asn Gln Thr Ala Asp Ser Ile Val Ile Asp Ala Leu