Key features of xylem vessel elements Steps:

• Xylem vessel elements conduct water and are dead at maturity, lacking cytoplasm and plasmodesmata.
• Lignified walls provide structural support to prevent collapse under tension.
• Pits in walls enable lateral water flow between adjacent elements.
• Mitochondria power cellular processes during development before cell death.

Why C is correct:

• By definition in plant anatomy, xylem vessel elements possess lignified walls for rigidity, pits for permeability, and mitochondria during differentiation for metabolic activity.

Why the others are wrong:

• A includes cytoplasm (2), absent in mature vessel elements.
• B omits pits (4), critical for water movement.
• D lists cytoplasm (2) and plasmodesmata (3), features of living phloem cells.

Final answer: C