[单选题]
Which is not a correct defi(a kh*dme x6pv 0qf)e 2c69q g,u4qq+yx1sslonition4be)6rc esoj4 or equation for water potential?
A. The sum of the solute and pressure potential of a solvent
B. ψ$_w$ = ψ$_s$ + ψ$_p$
C. The direction that water will move through a semipermeable membrane
D. The potential energy of water per unit volume
