The A$260/$A$280$ ratio for a DNA sample measured on a nanodrop was measured at $1\mathrm{.}62.$ What does this tell you about the purity of your sample?$$

Group of answer choices

a$)$ this sample is contaminated with a substance that absorbs highly at $280$

b$)$ this sample is pure

c$)$ this sample is somewhat pure, but might be contaminated with a substance that absorbs at $260$

d$)$ this sample is contaminated with a substance that absorbs highly at $230$