Water movement via apoplast pathway in roots

Steps:

• Water enters root hair cells by osmosis due to higher solute concentration inside cells.
• It moves laterally through cell walls and intercellular spaces in the apoplast pathway.
• Water potential gradient drives osmosis toward the endodermis, where it's lower due to Casparian strip.
• At endodermis, water crosses into symplast for further transport.

Why A is correct:

• Apoplast pathway allows diffusion through cell walls and osmosis down the water potential gradient, as defined by water moving from high to low potential without crossing membranes initially.

Why the others are wrong:

• B: Active transport is for ions, not water; vacuole-to-vacuole osmosis occurs in symplast, not primary path to endodermis.
• C: Osmosis doesn't occur through intercellular spaces; diffusion in cytoplasm is symplast, not main route.
• D: Symplast is cell-to-cell via cytoplasm; root pressure aids ascent but not initial movement to endodermis.

Final answer: A