Which of the following is a nucleoside?

✅Explanation:
A nucleoside is a molecule composed of a sugar (ribose in RNA or deoxyribose in DNA) linked to a nitrogenous base (like guanine, adenine, cytosine, thymine, or uracil). Adenosine is an example of a nucleoside; it consists of the sugar ribose bonded to the nitrogenous base adenine.

📌📌Other Options:
-Guanine: A nitrogenous base found in both DNA and RNA.
-Cytidine monophosphate (CMP): This is a nucleotide. A nucleotide has an additional phosphate group attached to the nucleoside (sugar + nitrogenous base).