Concept: This question tests your knowledge of floral morphology, specifically the arrangement and number of stamens, which is a key characteristic used in plant classification.

Why (D) is correct: Tetradynamous stamens are a specific arrangement where there are six stamens in total, with four longer stamens and two shorter stamens. This arrangement is characteristic of the family Brassicaceae (mustard family), to which Brassica (e.g., mustard, cabbage) belongs.

Why other options are wrong:

• (A) Chrysanthemum: Belongs to Asteraceae, which typically has syngenesious stamens (anthers united, filaments free).
• (B) Zinnia: Also belongs to Asteraceae, sharing similar stamen characteristics with Chrysanthemum.
• (C) Poppy: Belongs to Papaveraceae, which usually has numerous free stamens (polyandrous).

NEET Tip: Remember that tetradynamous stamens are a diagnostic feature for the Brassicaceae family. This specific arrangement is quite unique and often tested.

Correct Answer: (D)