D. both a and b
homozygous means that the genotypes would be the same. so, homo dominant (ex. RR) and homo recessive (ex. rr) would be considered purebred genotypes
Create and enforce regulations that limit fossil fuel burning by industries. use funds to understand why smoke and mold are causes of outdoor air pollutants. educate people about the threats to outdoor clean air from visible forms of air pollution.
5 is b because it makes more sense
