Shared structural features in phloem cells

Steps:

• Recall companion cells contain ribosomes for metabolic support and plasmodesmata for connection to sieve tubes.
• Recall phloem sieve tube elements contain ribosomes for function and plasmodesmata at sieve plates for continuity.
• Evaluate options: match presence of both features in each cell type.
• Confirm option B aligns with both features present in both cells.

Why B is correct:

• Phloem definition states companion cells and sieve tube elements both have ribosomes for synthesis and plasmodesmata for symplastic transport between them.

Why the others are wrong:

• A: Plasmodesmata are present in both, not absent.
• C: Ribosomes are present in both, not absent.
• D: Both ribosomes and plasmodesmata are present, not absent.

Final answer: B