(b) : Histones help in packaging of $DNA$. In eukaryotes, $DNA$ packaging is carried out with the help of positively charged basic proteins called histones. Histones are of five types -$H_1, H_2A, H_2B,H_3$ and $H_4$. $H_1$ is attached over the linker $DNA$. Histone contains a large proportion of the positivelycharged (basic) amino acids, lysine and arginine in their structure. $DNA$ is negatively charged due to the phosphate groups on its backbone. The result of these opposite charges is strong attraction and therefore, high binding affinity between histones and $DNA$.