Which of the Following Equations Represents the Total Water Potential $\Psi$

Which of the following equations represents the total water potential of a plant?

A) s² + p² = w²
B) $\Psi$ _s = $\Psi$ _p + $\Psi$ _w
C) $\Psi$ _p = $\Psi$ _w + $\Psi$ _s
D) $\Psi$ _w = $\Psi$ _p + $\Psi$ _s