Identify the sugars present in DNA and RNA

• DNA stands for Deoxyribonucleic Acid. Hence, the sugar present in DNA is 2-deoxyribose.
• RNA stands for Ribonucleic Acid. Hence, the sugar present in RNA is ribose.

Include the correct stereochemical form

In nucleic acids, the sugar units are present in the $\beta$-D form.

Therefore:

• DNA contains $\beta$-D-2-deoxyribose
• RNA contains $\beta$-D-ribose

Check the options

• A: $\beta$-D-2-deoxyribose, $\beta$-D-deoxyribose

  • RNA sugar is not deoxyribose. ❌

• B: $\beta$-D-2-deoxyribose, $\beta$-D-ribose

  • Matches DNA and RNA correctly. ✅

• C: $\beta$-D-ribose, $\beta$-D-2-deoxyribose

  • Reversed order. ❌

• D: $\beta$-D-deoxyribose, $\beta$-D-2-deoxyribose

  • RNA sugar is incorrect. ❌

Final Answer

The correct option is B: $\beta\text{-D-2-deoxyribose, }\beta\text{-D-ribose}$