Answer
C.
Work Step by Step
A. and B. are wrong because they mention extraneous things unrelated to water potential (membrane potential, gravity), and D. gives the opposite of the correct answer by mentioning a difference rather than a sum.
You can help us out by revising, improving and updating this answer.
Update this answerAfter you claim an answer you’ll have 24 hours to send in a draft. An editor will review the submission and either publish your submission or provide feedback.