The correct option is B Nucleosides
The molecules shown here are nucleosides. Nucleosides are ribose or deoxyribose sugar units linked to a nitrogenous base. Nucleotides on the other hand are phosphate derivatives of nucleosides and nucleic acids are polymers of nucleotides. Deoxyriboses are the sugar moieties of DNA. When the nucleosides are formed from ribose sugar, they are ribonucleosides and they form a part of RNA. Purines and pyramidines are the class of nitrogenous bases that bind to ribose or deoxyribose to form the nucleosides.