Concept: This question tests your basic understanding of leaf morphology, specifically identifying the main photosynthetic part of a typical leaf.

Why (D) is correct: The lamina (also known as the leaf blade) is the broad, flat, green, expanded part of the leaf. It is responsible for photosynthesis and contains the network of veins and veinlets that provide structural support and transport water, minerals, and food.

Why other options are wrong:

• (A) Petiole: The petiole is the stalk that attaches the leaf blade to the stem; it is not the expanded green part.
• (B) Node: A node is the point on a stem where a leaf, branch, or flower is attached, not a part of the leaf itself.
• (C) Stipule: Stipules are small, leaf-like appendages found at the base of the petiole in some plants; they are not the main expanded part of the leaf.

Common Mistake: Students sometimes confuse the petiole with the lamina, or the stipules with the main leaf blade.

NEET Tip / Mnemonic: Think of 'Lamina' as the 'Lawn' of the leaf – where all the green action (photosynthesis) happens!

Correct Answer: (D)