To solve this problem, we need to determine the percentages of the other three bases in sea urchin DNA, given that 17% of the bases are cytosine (C).$\newline$According to Chargaff's rules for double-stranded DNA:$\newline \bullet$The amount of adenine (A) is equal to the amount of thymine (T).$\newline \bullet$The amount of cytosine (C) is equal to the amount of guanine (G).$\newline$Given that C = 17%, it follows that G = 17% as well.$\newline$Since the total percentage of all four bases must equal 100%, we can write:$\newline$C + G + A + T = 100%$\newline$Substituting the known values:$\newline 17$This simplifies to:$\newline A + T = 100$Since A = T, we can divide the remaining percentage equally between A and T:$\newline A = T = \frac{66}{2} = 33\% \newline$Therefore, the percentages of the bases are:$\newline \bullet$G = 17%$\newline \bullet$A = 33%$\newline \bullet$T = 33%$\newline$This corresponds to Option 3: G 17%, A 33%, T 33%.