The most widely accepted theory for ascent of sap in trees is (a) capillarity (b) role of atmospheric pressure (c) pulsating action of living cell (d) transpiration pull and cohesion theory of Dixon and Jolly.
Option D Transpiration pull cohesion theory for ascent of sap in trees is most widely accepted. This concept was proposed by Dixon and Jolly, 1884. It is based up on three basic assumptions which are cohesion in between water molecules, continuity of water column and transpiration pull.