Correct option is C, 18.7% and 31.3%.
Because adenine and guanine are purines, and because the percentages of adenine and guanine in yeast DNA are mentioned in the table as 31.3% and 18.7%, respectively, and lines 6-7 say that "Two of the possible bases— adenine and guanine—are purines," choice C is the right answer.
The percentages of both purines, adenine and guanine, in yeast DNA are not stated in the other choices, which are A, B, and D.
Here is another question with an answer similar to this about purines in years DNA:
https://brainly.com/question/12499113
#SPJ4