$\text{RNA}$ and $\text{DNA}$ are chiral molecules, their chirality is due to:

$\text{DNA}$ and $\text{RNA}$ contain sugar moieties—$\text{D-2-deoxyribose}$ and $\text{D-ribose}$ respectively. These sugars are chiral because they contain multiple asymmetric carbon atoms. The nitrogenous bases are planar and achiral, and the phosphate groups are also achiral. Thus, the chirality of nucleic acids stems from the $\text{D-sugar}$ component.