Concept: This question tests your knowledge of modified adventitious roots, specifically those that become tuberous for food storage.

Why (A) Dahlia is correct: Dahlia possesses tuberous adventitious roots. These roots arise from the stem base and swell up irregularly to store food, forming clusters. They are adventitious because they do not develop from the radicle.

Why other options are wrong:

• (B) Radish: Has a fusiform taproot, which is a modification of the primary root.
• (C) Carrot: Has a conical taproot, which is a modification of the primary root.
• (D) Beet: Has a napiform taproot, which is a modification of the primary root.

Common Mistake: Students often confuse modifications of taproots with modifications of adventitious roots. Remember that taproots develop from the radicle, while adventitious roots develop from any other part of the plant.

NEET Tip: Focus on the origin of the root (radicle vs. other parts) to distinguish between taproot and adventitious root modifications. Examples like Dahlia (adventitious tuberous) vs. Carrot/Radish/Beet (taproot modifications) are frequently asked.

Correct Answer: (A)