Soil water potential per unit mass is expressed as

Answer: Option D

Soil water potential is defined as "the amount of work that must be done per unit quantity of pure water to transport reversibly and isothermally to the soil water at a considered point, an infinitesimal quantity of water from a reference pool.
Soil water potential is the sum of four different components: gravitational potential + the matric potential + the pressure potential + the osmotic potential.
Soil water potential per unit mass is expressed as L²T².