Identifying phloem in dicot stem cross-section

Steps:

• Examine vascular bundles in the stem's cortex region.
• Locate tissue external to xylem but internal to cortex.
• Identify sieve tubes and companion cells characteristic of phloem.
• Confirm position adjacent to cambium layer.

Why B is correct:

• Phloem transports sugars downward and lies outside xylem in vascular bundles, as per plant anatomy definitions.

Why the others are wrong:

• A: Epidermis, the outer protective layer without transport cells.
• C: Xylem, inner water-conducting tissue with vessels and tracheids.
• D: Pith or cortex, central storage area lacking sieve elements.

Final answer: B