Concept: This question tests your understanding of aestivation, specifically the characteristics of vexillary or papilionaceous aestivation found in the family Fabaceae (legumes).

Why (D) is correct: In vexillary aestivation, the largest petal is actually posterior (standard or vexillum) and overlaps the two lateral petals (wings). The statement says the largest petal is anterior, which is incorrect.

Why other options are wrong:

• (A) Two smallest anterior petals are known as keel: This is correct. The two anterior petals are fused to form the keel.
• (B) Two lateral petals are known as wing: This is correct. The two lateral petals are called wings.
• (C) Pea plant is an example of vexillary aestivation: This is correct. Pea (Pisum sativum) is a classic example of vexillary aestivation.

Common Mistake: Students often confuse the position (anterior/posterior) of the standard petal in vexillary aestivation.

NEET Tip: Remember the arrangement: Standard (posterior) > Wings (lateral) > Keel (anterior). A simple way to visualize is that the 'Standard' petal stands at the back, covering the others.

Correct Answer: (D)