Monoadelphous refers to stamens united by their filaments into a single bundle.

• A. Monoadelphous
• B. Diadelphous
• C. Polyadelphous
• D. Synandrous

Answer: (A)

Stamens can be joined by their filaments in different ways, and the term used here describes when all the filaments fuse into one single stalk. That is monadelphous: all the stamens are united into one bundle, often forming a tube around the style as seen in some plant families. This pattern is distinct from two bundles (diadelphous) or several bundles (polyadelphous), where the filaments divide into separate groups. Synandrous refers to a different kind of fusion among the stamens, typically a more general fusion that isn’t described as a single filament bundle around the style. So the description best matches monadelphous.