Problem: A biologist wanted to determine the pattern of spontaneous mutations in mammals. She performed pairwise comparisons between processed pseudogenes and their functional counterparts in human, and found that most nucleotide substitutions involve a C or G in the functional gene changing to A or T in pseudogenes. Is this finding consistent with the following possibilities: A) Genome-wide spontaneous mutations in human genome were AT-biased. B) Given that human genome has gene-rich segments with GC-biased mutation and gene-poor segments with AT-biased mutation, most pseudogenes may result from functional genes from GCrich regions re-inserted into AT-rich regions C) both A) and B) D) none of the above