Which of the following statements about mutations is most accurate? a. whether or not a mutation occurs is not related to how useful or harmful the mutation may be. b. it is finally accepted and recognized that mobile phones are a large contributor to mutations, specifically in the head and neck region, and largely contribute to brain tumors. c. mutations are a minute source of genetic variation in a population. mutations can change alleles, but they do not have the power to create a completely novel allele. d. mutations tend to slow down evolutionary advancement, whereas natural selection demonstrates evolutionary growth.