13. Which of the following is true about a circular double-stranded DNA genome that is determined by chemical means to be 21 percent adenosine? (A) The genome is 10.5% guanosine. (B) The genome is 21% guanosine. (C) The genome is 29% guanosine. (D) The genome is 58% guanosine. (E) The base percent composition of guanosine in the genome cannot be determined from the information given.