Understand that pentose sugars are five-carbon sugars important in nucleic acids.
Recall that RNA (ribonucleic acid) contains a specific pentose sugar that distinguishes it from DNA.
Identify the pentose sugar in RNA by remembering that it has a hydroxyl group (-OH) attached to the 2' carbon, unlike DNA.
Recognize that the sugar with this characteristic is called ribose.
Confirm that the other options (glucose, deoxyribose, fructose) are either not pentose sugars or are associated with other molecules (e.g., deoxyribose is found in DNA).