Task: Instance Description Understanding (ontology: Earth_Environment/SWEET)

Which of the following definitions best describes the instance 'specific yield'?

A. A relationship between the advective and diffusive components of solute transport expressed as the ratio of the product of the average interstitial velocity, times the characteristic length, divided by the coefficient of molecular diffusion; small values indicate diffusion dominance, large values indicate advection dominance.
B. An approximation to the gradient Richardson number formed by approximating local gradients by finite difference across layers.
C. The ratio of the volume of water which the porous medium after being saturated, will yield by gravity to the volume of the porous medium.
D. The ratio of the Volume of water which the porous medium, after being saturated, will retain against the pull of gravity to the volume of the porous medium.

Answer: The ratio of the volume of water which the porous medium after being saturated, will yield by gravity to the volume of the porous medium.