Matching adaptations to phloem and xylem cell types

Steps:

• Companion cells have many plasmodesmata for communication and nutrient exchange with sieve tubes.
• Phloem sieve tube elements possess a thin layer of cytoplasm to minimize resistance during sap flow.
• Xylem vessel elements are empty, dead cells enabling unobstructed water transport.
• Option C correctly sequences these: plasmodesmata (companion), thin cytoplasm (sieve tubes), empty cells (xylem).

Why C is correct:

• Aligns with plant transport tissue anatomy, where companion cells connect via plasmodesmata, sieve tubes streamline flow with minimal cytoplasm, and xylem vessels provide open conduits per the cohesion-tension theory.

Why the others are wrong:

• A: Misassigns lignified walls to companion cells, which are living and unlignified.
• B: Incorrectly attributes empty cells to phloem and plasmodesmata to xylem, reversing tissue roles.
• D: Swaps order, assigning lignified walls to companion cells instead of xylem.

Final answer: C