Which of the following inferences made from phylogenetic analyses of the nurse's and patient's HIV sequences from the RT gene (reverse transcriptase) allowed for the conclusion that the nurse was infected by the patient's HIV virus, rather than the other way around?
A) Longer branch length in the patient's sequence
B) Presence of identical nucleotide substitutions in both sequences
C) Phylogenetic tree topology
D) Lower genetic diversity in the nurse's sequence
