In sea urchin DNA, which is double-stranded?

According to Chargaff’s rule all cellular DNAs, regardless of the species, number of adenosine residues is equal to number of thymidine residues which means that A=T; and the number of guanosine residues is equal to the number of cytidine residues; G= C. In the given question, there is 17% of T. Since A=T, then A = 17%. This leaves 100% - 17% -17% = 66% for G and C. Since G=C, then G= 33% and C=33%. Therefore the correct answer is T - 17