Oxygen-rich blood enters the right atrium is pumped to the body by the left ventricle is pumped to the lungs by the right ventricle passes from the right ventricle into the left atrium

Why do rna viruses appear to have higher rates of mutation? a) rna nucleotides are more unstable than dna nucleotides.b) replication of their genomes does not involve proofreading.c) rna viruses can incorporate a variety of nonstandard bases.d) rna viruses are more sensitive to mutagens.