The correct answer is option-1, Pentose sugar. DNA, or deoxyribonucleic acid, is a molecule that contains genetic instructions for the development and functioning of all living organisms. It is composed of nucleotides, which consist of three main components: a phosphate group, a nitrogenous base, and a sugar molecule. In the case of DNA, the sugar molecule is a type of pentose sugar called deoxyribose. Pentose sugars have five carbon atoms in their structure, and deoxyribose specifically has one less oxygen atom compared to ribose, which is the sugar found in RNA. Hexose sugars, on the other hand, have six carbon atoms and are not present in DNA. Therefore, option 2, 3, and 4 are incorrect.