Concept: This question tests knowledge of specific floral characteristics, particularly the arrangement of stamens, and their association with plant families.

Why (D) is correct: The tetradynamous condition, characterized by six stamens (four long and two short), is a distinctive feature of the family Brassicaceae (mustard family). Brassicaceae is also known for having parietal placentation and typically tetramerous flowers (parts in fours or multiples of four, though stamens are six). Therefore, option D accurately describes the family where tetradynamous condition is observed.

Why other options are wrong:

• (A) Potato family (Solanaceae): Typically has five stamens, not tetradynamous.
• (B) Asparagus family (Asparagaceae, formerly Liliaceae sensu lato): Usually has six stamens of equal length, not tetradynamous.
• (C) Grass family (Poaceae): Typically has three stamens, not tetradynamous.

NEET Tip: Remember that tetradynamous stamens are a hallmark of Brassicaceae. Associating specific floral characteristics like placentation type and stamen arrangement with particular families is crucial for NEET.

Correct Answer: (D)