Multiple choice Most widely accepted explanation for the ascent of sap in plant is capillarity / Imbibition pulsating activity of living cells role of atmospheric pressure transpiration-cohesion theory Reveal answer Fill a bubble to check yourself D Correct answer Explanation The transpiration-cohesion-tension theory is the most widely accepted explanation for how water moves upward through the xylem against gravity. It relies on the cohesive properties of water and the pull generated by transpiration.