• Diffusion Pressure Deficit ($DPD$), term coined by B.S. Meyer (1938), represents the suction force of a plant cell.
• It is mathematically defined as:
  $$DPD = OP - TP$$
  where $OP$ is Osmotic Pressure and $TP$ is Turgor Pressure (equal to Wall Pressure $WP$).
• Under modern thermodynamic conventions, $DPD$ corresponds to $-\Psi_w$, where $\Psi_w = \Psi_s + \Psi_p$.

• (A) is false: Sandy soils are dominated by macropores which drain rapidly by gravity; thus their water holding capacity is low.
• (B) is true: Silt loam and silty soils have a balanced pore size distribution with high available water holding capacity.
• (C) is false: Clay soils possess high microporosity and large specific surface area, giving them the highest total water holding capacity.
• (D) is true: Clay soils have small micropores that restrict gas diffusion and percolation, leading to poor aeration and drainage.
• (E) is true: Texture and organic matter are the two primary determinants of water retention.

Both statements are true:

• Statement (I): Upward capillary movement transports water from subsurface moist layers to the dry evaporating soil surface, driving continuous evaporative loss until the capillary continuity is broken by mulching or surface tillage.
• Statement (II): Soil retains water against gravitational drainage via matric suction governed by adhesion (attraction between soil solid surfaces and water molecules) and cohesion (attraction among water molecules themselves, giving rise to surface tension).