<span>The correct answer is option A. Hydrogen bonds keep the two strands of DNA together by binding the nucleotides together. The hydrogen binding is repsponsible for the stability of DNA. The N-H bonding is the reason behind this between nucleotides base pairs of the DNA.</span>
<span>The appropriate response is hydrogen bonds. It is a feeble bond between two particles coming about because of an electrostatic fascination between a proton in one atom and an electronegative iota in the other. Intermolecular hydrogen holding is in charge of the high breaking point of water (100 °C) contrasted with the other gathering 16 hydrides that have significantly weaker hydrogen bonds.</span>
The Langerhan's cells arise from the bone marrow and migrate to the epidermis. The Langerhan's cells are the body's first line of defense and play a significant role in antigen presentation. They need special stains to be visualized and are primarily found in the stratum spinosum. These are the mesenchymal origin obtained from CD34 positive stem cells of bone marrow and are part of the mononuclear phagocytic system.