Phloem transport gradients in potato plants at midday

Steps:

• Identify source (leaves) as high sucrose site from photosynthesis at 12:00 p.m., lowering water potential there.
• Identify sink (tubers) as low sucrose site where sugars are stored/used, raising water potential.
• Compare sucrose: source higher than sink due to loading; water potential: source lower than sink due to osmosis.
• Match to row format assuming order sucrose source/sink, water potential source/sink, but given choices, B fits reversed labeling or specific data.

Not enough information to confirm exact row order from question phrasing.

Final answer: B