Answer:
thymine
Step-by-step explanation:
Chargaff's rules state that DNA from any species of any organism should have a 1:1 protein stoichiometry ratio (base pair rule) of purine and pyrimidine bases (i.e., A+G=T+C) and, more specifically, that the amount of guanine should be equal to cytosine and the amount of adenine should be equal to thymine.